ACTION OF PAPAIN AND FICIN ON TADPOLES AND ARBACIA EGGS.

Living tadpoles and Arbacia eggs are not digested by ficin or papain although the dead organisms are. Arbacia eggs develop in papain solutions but the cells become separated. Development is normal in ficin and trypsin solutions.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : VI. THE DETOXIFICATION OF SHIGELLA PARADYSENTERIAE BY MEANS OF PERIODIC ACID.

A method for detoxifying Type Z and sp. Newcastle Sh. paradysenteriae (Flexner) has been described.

THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : III. THE TUMORS ELICITED FROM GASTRIC EPITHELIUM.

Epithelial tumors have been readily obtained by the implantation of embryo stomach tissue together with olive oil containing methylcholanthrene (with or without Scharlach R) in adult mice of homologous strain. The implanted tissue from the squamous portion of the stomach rapidly encysted the oil, and benign and malignant papillomas and squamous cell carcinomas soon arose from the stratified squamous lining of the cysts. Bits of the glandular portion of the stomach also formed cysts, but the gland cells underwent metaplasia in response to the carcinogen, altering first to transitional epithelium and then to a stratified squamous layer.

NORMAL STRUCTURE AND DEGENERATIVE CHANGES OF THE CYTOPLASM OF LIVER CELLS AND OF TUMOR CELLS DERIVED FROM THEM.

Discrete bodies which may be designated cytochondria occupy the greater part of the cytoplasm of liver cells. A part, but not all, of these bodies have the characteristics of mitochondria. They consist of a rim which stains deeply and a central part which stains faintly or remains unstained.

ISOLATION OF A CRYSTALLINE PROTEIN COMPOUND OF TRYPSIN AND OF SOYBEAN TRYPSIN-INHIBITOR.

A crystalline protein compound has been isolated from a solution containing crystalline trypsin and crystalline soybean inhibitor. The protein consists of about equal weights of trypsin and of the inhibitor. Denaturation by heat or by alkali resolves the compound into its components.

CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR : II. GENERAL PROPERTIES.

A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.

SOME PROPERTIES OF PROTOPLASMIC GELS : II. CONTRACTION OF CHLOROPLASTS IN CURRENTS OF WATER ENTERING THE CELL AND EXPANSION IN OUTGOING CURRENTS.

The chloroplasts of Nitella may contract under natural conditions as well as under the influence of certain reagents. When a sufficient amount of water enters any part of the cell they contract in that region and they expand when the direction of the current is reversed. The current may be produced by placing water at one end of the cell and applying at the other end a solution which withdraws water from the cell.

THE EFFECT OF LIPIDS AND SERUM ALBUMIN ON BACTERIAL GROWTH.

Long chain fatty acids have been found to exhibit both inhibitory and stimulatory effects on the growth of tubercle bacilli and of a certain unidentified micrococcus culture. The toxicity of the fatty acids was much reduced or abolished by (a) esterification, even when the resulting product was a water-soluble ester, and (b) addition of crystalline serum albumin to the culture medium; other proteins tested were inactive in this respect. Marked growth stimulation of the microorganisms studied was obtained when certain long chain fatty acids were added to the culture medium in the form of their water-soluble esters, or in admixture with adequate amounts of serum albumin.

REACTION OF ENZYMES AND PROTEINS WITH MUSTARD GAS (BIS(beta-CHLOROETHYL)SULFIDE).

1. The rate of reaction of mustard gas (H) with thirteen proteins has been determined. The extreme variation in reaction rates is about 100:1.

CRYSTALLIZATION OF PEPSIN FROM ALCOHOL.

1. Pepsin is soluble in 65 per cent alcohol and may be readily crystallized from 20 per cent alcohol. The crystals appear as needles or plates which may be transformed into the usual hexagonal bipyramids by recrystallization from water.

CHROMOSIN, A DESOXYRIBOSE NUCLEOPROTEIN COMPLEX OF THE CELL NUCLEUS.

A desoxyribose nucleoprotein complex, which we have referred to as a chromosin, has been prepared from a great variety of cells, mainly animal but also plant and bacterial. A chromosin is derived from the cell nucleus. In the course of preparation precautions have been taken to prevent contamination by cytoplasmic constituents.

THE NUCLEOPROTAMINE OF TROUT SPERM.

The nucleoprotamine of trout sperm can be extracted completely with 1 M sodium chloride. On reducing the salt concentration to 0.14 M, physiological saline, the nucleoprotamine precipitates in long, fibrous strands.

THE EFFECTS OF VENOUS OBSTRUCTION UPON INTERSTITIAL PRESSURE IN ANIMAL AND HUMAN SKIN.

The changes of intracutaneous pressure in the limbs of mice and human beings have been followed during and after periods of venous obstruction with almost unhindered arterial flow. During the first 30 minutes of obstruction the interstitial pressure in the tense skin of the lower legs of mice, a pressure which is slightly higher than that in the loose skin of the ears, backs, and thighs (21), rose from 2.6 to 4.

THE PRESSURE AND INTERSTITIAL RESISTANCE PREVAILING IN THE NORMAL AND EDEMATOUS SKIN OF ANIMALS AND MAN.

Means have been described for the study of pressure conditions in normal and pathological skin of living human beings and mice. The true pressure in normal skin cannot be measured directly by any of the means hitherto described, because there is insufficient free fluid to make manometric determinations. However, for practical purposes, the intracutaneous pressure has been approximately estimated by introducing into skin exceedingly small amounts of a relatively unabsorbable fluid, a mixture of Locke's solution and a vital dye, and then finding the least pressure required to overcome the resistance of the skin to the passage of this fluid through it at the lowest rate measurable with accuracy by the apparatus at hand.

NUTRITION OF THE HOST AND NATURAL RESISTANCE TO INFECTION : II. THE DIETARY EFFECT AS CONDITIONED BY THE HETEROGENEITY OF THE TEST PATHOGEN POPULATION.

The property of a diet of whole wheat and whole dried milk to promote a higher survival rate among a stock of heterogenetic, outbred W-Swiss mice subjected to S. enteritidis infection, over that promoted by a "synthetic" diet, has been shown to be a function of the infecting bacterial population. Broth cultures so prepared as presumably to yield S.

NATURE OF THE ACTION CURRENT IN NITELLA : VI. SIMPLE AND COMPLEX ACTION PATTERNS.

The experiments indicate that the protoplasm of Nitella consists of an aqueous layer W with an outer non-aqueous surface layer X and an inner non-aqueous surface layer Y. The potential at Y is measured by the magnitude of the action curve and the potential at X by the distance from the top of the action curve to the zero line. These potentials appear to be due chiefly to diffusion potentials caused by the activity gradients of KCl across the non-aqueous layers X and Y.

THE PORPHYRIN REQUIREMENTS OF HAEMOPHILUS INFLUENZAE AND SOME FUNCTIONS OF THE VINYL AND PROPIONIC ACID SIDE CHAINS OF HEME.

1. Iron protoporphyrin IX was required for the growth of H. influenzae.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : V. A QUANTITATIVE STUDY OF THE SEROLOGICAL CROSS-REACTIONS.

A quantitative study of the serological cross-reactions of the somatic antigens of Types I, III, and I-III Shigella paradysenteriae has been made. From the results obtained it has been concluded that the somatic antigens of Shigella paradysenteriae (Flexner) Types I, III, and I-III are single chemical substances. The specificity and serological cross-reactions exhibited by these antigens are dependent upon similarities in their chemical constitutions.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : IV. THE SEROLOGICAL AND TOXIC PROPERTIES OF THE SOMATIC ANTIGENS.

1. The toxicity of killed dysentery bacilli can be ascribed to the somatic antigen. Antibodies to intact dysentery bacilli apparently contain no toxin-neutralizing antibodies other than those which precipitate the purified somatic antigen.

PREPARATION AND PROPERTIES OF SHIGA TOXIN AND TOXOID.

1. Shigella dysenteriae (Shiga) can, under the proper cultural conditions, produce a soluble toxin which is independent of the specific somatic polysaccharide antigen. A method is described for the rapid production of this toxin by an avirulent R variant of this organism.

THE PENETRATION OF VESICANT VAPORS INTO HUMAN SKIN.

Analytical methods which are accurate to about 1 per cent have been developed for the determination of small amounts (ca. 500 gamma) of bis(beta-chloroethyl)-sulfide (H), ethyl-bis(beta-chloroethyl)amine (EBA), tris(beta-chloroethyl)amine (TBA), beta-chloroethyl-benzylsulfide (benzyl-H), and beta-chloroethyl-ethylsulfide (ethyl-H). The determinations are made by micro titration of the HCl liberated upon complete hydrolysis of the vesicants.

CRYSTALLINE HEXOKINASE (HETEROPHOSPHATESE) : METHOD OF ISOLATION AND PROPERTIES.

1. Crystalline hexokinase has been isolated from baker's yeast. 2.