ANNUAL REPORT, 1038 103 



decomposition was apparently completely checked by holding the samples 

 in a frozen condition. At a given temperature there was httle significant 

 increase in the rate of decomposition of ground, defrosted fish when com- 

 pared with a similar sample which had not been frozen. 



307 Time interval between clutches in Rhode Island Red pullets. F. A. Hays. 

 Jour. Agr. Research 57 (8):575-581. 1938. 



The relation of time interval between clutches to a number of fecundity 

 and reproductive characters was studied. The various relationships 

 observed led to the conclusion that, in a breeding program, short time 

 intervals between clutches in winter should be placed along with short 

 time intervals between eggs of a clutch as a desirable character. 



308 Factors influencing the rate of decomposition of different types of plant 

 tissue in soil, and the effect of the products on plant growth. Major F. 

 Spaulding and Walter S. Eisenmenger. Soil Science 45 (6):427-445. 1938. 



The object of the investigation was to establish by e.\perimental methods 

 principles by which the characteristics and relative values of natural 

 fertilizers (humus) could be estimated in advance of use from their known 

 or discoverable chemical constituents. A partial chemical analysis (in- 

 cluding determinations of the proportions of nitrogen, carbon, lignin, and 

 pentosans) was made of 43 different plants and 2 seed parts, and their 

 decomposition studied under different conditions in the greenhouse. On 

 the whole, the plants containing most nitrogen decomposed more readily. 

 The structure of plants and their content of lignin and pentosans were 

 also factors in the rate of decomposition. If the ratio of nitrogen to 

 carbon was not more than 1 to 25-30, the plants decomposed easily, but 

 if the ratio was wider, the incorporation of the plants in the soil resulted 

 in a depression of the nitrates. 



313. Preliminary report on infectious avian encephalomyelitis. H. Van Roekel, 

 K. L. Bullis,and M. K. Clarke. Jour. Amer. Vet. Med. Assoc. 93 (n.s. 46): 

 372-375. 1938. 



During the last few years the incidence of infectious encephalomyelitis 

 in chickens apparently has increased. The geographical distribution of 

 the disease is not known, but the greatest incidence has been reported 

 among flocks in the New England States. The disease is caused by a 

 filtrable, infectious agent. Field and laboratory evidence suggests 

 that the infective agent may be egg-borne and that the breeding stock 

 may serve as the reservoir of infection. 



316 Diseases of nursery plants: Infectious and noninfectious diseases of ever- 

 green and dedicuous trees in the open. Malcolm A. McKenzie. Amer. 

 Nurseryman 68 (7): 3-4. 1938. 



Noninfectious diseases discussed are needle blight, a disease of eastern 

 white pine, and a disease caused by smoke. The cause of needle blight 

 is not known, but the characteristic symptoms which differentiate it from 

 other needle injuries caused by fungi or insects are described. Ever- 

 greens are more sensitive to smoke injury than are deciduous trees, but 

 the latter may be aff^ected. Several infectious diseases are discussed, 

 with suggestions for the protection of nursery trees; and particular warn- 

 ing is given of the dangers of the Dutch elm disease. 



323 Effect of riboflavin and thiamin chloride upon the cataractogenic action of 

 galactose. Helen S. Mitchell and Gladys M. Cook. Proc. Soc. Expt. 

 Biol, and Med. 39:325-326. 1938. 



In previous work with galactose cataract the usual protective doses of 

 vitamin supplements were provided in accordance with the recognized 

 need of the rat. The normal growth of the rats and the lack of gross 

 evidence of any vitamin deficiency led to the conclusion that the cataract 

 was probably due to some metabolic disturbance unrelated to a vitamin. 

 However, it was recognized that the introduction of galactose might have 

 created unusual demands for certain vitamins. In this investigation 

 riboflavin and thiamin chloride, two crystalline fractions of the vitamin B 

 complex, were fed in varying amounts up to massive doses. Neither 

 riboflavin nor thiamin chloride exerted any protective action against the 

 development of galactose cataract in rats. 



