60 EXPERIMENT STATION EECOED. [VoL37 



There are two generations a year, parthenogenesis apparently being the usual 

 method of reproduction. The adults of the first generation appear in greatest 

 frequency between the third week in June and the middle of July, and of the 

 second generation between the middle of August and the first week in Sep- 

 tember. The efficiency of this parasite is said to be far below that of the 

 most effective insecticides, due primarily to four factors, namely, its extremely 

 limited powers of migration, its relatively low fecundity, its marked suscepti- 

 bility to the influence of unfavorable climatic conditions, and the effects of the 

 second annual generation of parasitism being only partial and incomplete. 



A list of 33 references to the literature is included. 



FOODS— HTIlilAN NUTEITION. 



The use of cotton seed as food, T. B. Osbobne and L. B. Mendel (Jour. Biol. 

 Chem., 29 {1011), A'o. 2, pp. 280-317, figs. 5).— This paper reports data cora- 

 plle<^i from experiments with laboratory animals (rats) which were fed cotton- 

 seed products of various descriptions. The following facts were established 

 as results of ihese experiments : 



Cottonseed kernels were found to be unsatisfactory for nutrition. All of 

 the animals receiving this product in the ration died within two weeks. The 

 .samples of cotton.seed meal and flour te.«;ted were found to be valuable foods 

 for growing rats, both when used as a sole source of protein In the diet and 

 when used in smaller quantity to supplement their less efficient protein con- 

 centrates. 



The injurious substances in the kernels can be removed by extraction with 

 ether and, according to other investigators, by extraction with carbon bisulphld, 

 chloroform, benzene, or alcohol, but not with petroleum ether or gasoline. 

 I'he ether-soluble material Is deleterious, either because It contains some toxic 

 ingredients or else because It renders the food so unpalatable that the animals 

 refuse to eat it. Foods containing cottonseed oil prepared by cold pressing 

 or the crude unbleached commercial oil prepared by hot pressing were eaten 

 witlvnut detriment by the rats. 



" By treatment with steam under suitable conditions the kernels lose their 

 deleterious effect on rats. The variations in the results of feeding different 

 samples of cottonseed meal, which have been reported, may be due to dif- 

 ferences in the mode of heating which the products have experienced in their 

 preparation." 



With regard to the question as to whether cottonseed injury in the feeding 

 of domestic animals can be cla.ssed with the deficiency diseases, the authors 

 state that it is possible that food mixtures lacking some of the now recognized 

 essential ingredients of an adequate diet have been employed In the past Ex- 

 periments with rats which were grown successfully on cottonseed rations ex- 

 cluded the probability that there Is ordinarily any lack of the water-soluble 

 vitamin. There Is no definite information that the quota of Inorganic salts 

 furnished In agricultural products is always sufficient. 



The authors have "induced young rats to double their weight at a normal 

 rate of growth on a food mixture containing nothing except cottonseed meal, 

 starch, and lard. The deleterious effects of unheated cottonseed kernels can 

 not be denied. Whether the reputed detrimental effect after feeding .<!onie of 

 the commercial cottonseed meals Is associated with a failure to destroy a 

 deleterious constituent — as has been Indicated above — or is attributable to un- 

 suitable methods of feeding in some cases Is still debatable. The treatment 

 of the cotton seed so as at least to render It harmless now seems to lie within 

 the range of ready possibilities." 



