866 EXPERIMENT STATION RECORD. [Vol. 43 



Poisoning following the eating of solanin-containing potatoes, J. C. 



RoTHK (Ztschr. Hyg. u. Infektionskrank., S8 (1919), No. 1, pp. 1-12).— The 

 author reports 14 cases of illness occurring in Leipzig in February, 1918, as a 

 result of eating potatoes containing about 3.8 per cent of solanin. A brief 

 review of the literature on solanin poisoning is included. 



ANIMAL PRODUCTION. 



The generative value of an individual as estimated by the method of 

 dlallel crossing, J. Schmidt (Compt. Rend. Lab. Carlsberg, H (1919), No. 6, pp. 

 34). — By diallel crossing is meant any method of experimental breeding whereby 

 offspring of known parentage are secured from all possible matings of several 

 males and several females of any animal or plant form in which such matings 

 are possible. If a particular quantitative character is measured in all the off- 

 spring, the author shows that it is possible to assign to each parent a numerical 

 value for the character in question which represents the individual's transmit- 

 ting or generative value as distinct from the personal value determined by 

 measuring the character as it is manifested in the individual. 



One of the original males or females is selected as the basis of reference and 

 its transmitting value is assigned an arbiti'ary number, usually the individual's 

 personal value. The transmitting values of the remaining parents are treated 

 as unknowns, and are found by solving a set of equations in which- the average 

 measurement of the offspring of each pair is considered equal to the average 

 of the transmitting values of the two mates. 



The author points out that the method can not be used if the characters dealt 

 with show dominance, and he is aware of various practical limitations. How- 

 ever, the method is considered useful in the study of the inheritance of quanti- 

 tative characters where it can be applied. Mention is made of a possible prac- 

 tical application in testing the relative capacities of boars and sows to produce 

 rapidly growing pigs. 



Racial studies in fishes. — m, Diallel crossings with trout (Salmo trutta 

 L.), J. Schmidt (Jour. Genetics, 9 (1919), No. 1, pp. 61-67). — The author re- 

 ports a study of the number of vertebrae in the trout by his method of diallel 

 crossing. The arithmetical process of determining the generative values of the 

 parents is also explained, but for an exposition of the general utility of the 

 method of diallel crossing it is necessary to consult the publication noted above. 



On certain factors concerned in the production of eye color in birds, 

 C. J. Bond (Jour. Genetics, 9 (1919), No. 1, pp. 69-81).— The author reports 

 histological observations on the irides of pigeons, domestic fowl, and other 

 birds and states the results of some of his breeding experiments. 



In the bull eye and the pearl eye of pigeons and in the daw eye of the Malay 

 fowl no pigment occurs in the outer stroma of the iris. The bull eye is dark be- 

 cause the inner pigmented layer is visible through the translucent stroma, while 

 the pearl eye and the daw eye are light in color because the pigmented layer is 

 obscured by opaque colorless granules in the stroma. All other eye colors are 

 brought about by pigment granules in the stroma. There is usually a net- 

 work of branching cells covered with small spherical granules, and similar 

 granules surround the capillary blood vessels and striated muscle fibers, in 

 the yollow or gravel eye of pigeons, the ruby eye of ring doves, and the eyes 

 of Buff Orpington and Dorking fowls these granules are yellow. In brown or 

 black eyed birds the granules are dark brown or black. In some breeds of 

 poultry, such as the Silky, the Croad Langshan, and the Houdan, both black 

 and yellow granules occur in the stroma. 



