24 



The Journal of Heredity 



tigation of the cflfect of inbreeding on 

 fertility. 



At the Massachusetts station the 

 poultry department is using both fowls 

 and ducks in an endeavor t(j get as much 

 genetic information as possible, the 

 principal point under consideration 

 being the inheritance of fecundity. An 

 investigation is also being carried out on 

 the inheritance of hatching power of 

 eggs, of comb form, color and color 

 patterns, shank feathering and rate of 

 growth. Some of the latter researches 

 parallel those that have been made by 

 Bateson, Davenport and other investi- 

 gators, the Massachusetts station desir- 

 ing to confirm or apply their results, and 

 to find satisfactory interpretations for 

 the new facts observed. 



Influence of management and feeding 

 on vigor of germ in hen's eggs has been 

 investigated in West Virginia. The 

 data already in hand indicate that chicks 

 are less \^igorous when hatched from 

 eggs laid by hens which have been 

 laying heavily for a long time. 



A study of inheritance in the honey 

 bee has been pursued in Texas for 

 several years. 



The Porto Rico station is improving 

 native cattle by crosses wnth zebu 

 hybrids brought from Texas. 



As a result of hybridizing wild and 

 tame cavies for past six years, the 

 Illinois station has reached some inter- 

 esting conclusions which have just been 

 published by the Carnegie Institution 

 of Washington^ (publication no. 205). 

 The investigators are convinced that the 

 Mendehan mode of inheritance prevails 

 for individual characters in species 

 crosses in mammals in the same way as 

 in variety crosses, contrary to what has 

 sometimes been asserted. Many differ- 

 ent characters have been studied and 

 their mode of inheritance is reported in 

 this paper. Fertility in the male hy- 

 brids seems to be a very complex 

 character which segregates out in the 

 Mendelian fashion. At j^resent work 

 of selection and hyl)ridization is under 

 way with mice and other small mammals. 

 There has been room for plenty of more 

 practical work, for over a million cows 



are kei:)t for dairy purposes in Illinois, 

 of which not more than 2% are purebred. 

 The station has induced many breeders 

 to add jjurebred bulls to their herds and 

 is endea\-oring to get as many cows as 

 possible accurately tested, although at 

 present only a fraction of 1% of the total 

 number can show accurate records of 

 production, kept either officially or 

 privately. "It should be considered 

 little less than a crime to u.se a scrub 

 bull, or one whose dam has not produced 

 300 lbs. of butter fat in 365 days," the 

 breeders are told, and they are gradually 

 taking the advice to heart. 



TO PRODUCE BROWN EGGS 



By crossing suitable breeds, the 

 Maryland station has undertaken to 

 produce a breed of general utility fowl 

 that will lay a white shelled egg. The 

 superior market value of the white egg 

 over that with a brown shell is well 

 known; and although the preference 

 seems to be wholly irrational, breeders 

 must be prepared to meet the situation. 

 Unfortunately the breeds that lay w^hite 

 eggs are, as a rule, small and ill adapted 

 for marketing. It should be possible 

 to transfer the capacity to produce white 

 shelled eggs (which seems to be a 

 Mendelian character) to a breed that 

 will also make good "broilers." It is 

 this task which the Maryland station 

 has undertaken. 



Heredity in sheep is being studied in 

 New Hampshire, observations on the 

 mode of inlieritance in horns having 

 already been published. In cattle, the 

 polled condition seems to be a regular 

 Mendelian dominant except that, ac- 

 cording to Spillman, the dominance is 

 not entirely complete in male hetero- 

 zygotes. In sheep, the inheritance of 

 horns does not follow the same rules, 

 although it is thought by many students 

 to follow an equally simple system. 

 The New Hampshire station has worked 

 princii)ally with Merinos, and in order 

 to interpret its data has j^ostulated two 

 "detemiiners" in the germ cell, the 

 behavior of which differs in each sex, 

 and has also ])ostulated the presence of 

 hypothetical "inhibitors," which further 



* Most of the actual breeding, results of which arc reported in thin publication, was done at 

 the Bussey Institution, Forest Hills, Mass. 



