DEPARTMENT OF EXPERIMENTAL EVOLUTION. 79 



DETAILED REPORTS ON SCIENTIFIC WORK. 



WORK ON HEREDITY IN ANIMALS. 



Poultry. — In continuation of the experiments with poultry, 53 pens were 

 maintained and over 3,500 chicks hatched. Fireless brooders were used ex- 

 clusively for the outdoor brooding with entire satisfaction. Progress was 

 made in developing rumpless, nailless, syndactyl, polydactyl, and combless 

 strains ; also new forms of comb, nostril, and boot. Several sets of experi- 

 ments on potency and reciprocals were undertaken, and the results of graft- 

 ing and abnormal temperatures studied. 



Finches. — The breeding of canary birds was continued but, owing to the 

 use of many young birds this year, the fecundity was small, only about 30 

 being reared. Interesting results were gained from the second hybrid gener- 

 ation of Java sparrows, since nearly pure white (with a little smokiness) 

 were obtained from the gray hybrids of the first generation. 



Sheep and Goats. — Fourteen sheep and six goats were born. The lop ear 

 of the Indian goat is dominant over erect ear of the Irish goat as truly as 

 accessory auricles are dominant over their absence. The black ram with 6 

 nipples, from Mr. Alexander Graham Bell's flock, is being replaced by a 

 4-horned, 3-nippled sheep, also a gift to the station from Mr. Bell. 



Cats. — The new cat-house has proved well adapted to its purposes and 

 the health and fertility of the stock are much improved. 



WORK ON PLANTS. 



The continuation of Dr. Shull's experiments was confided to the care of 

 Mr. R. Catlin Rose, for whose guidance Dr. Shull prepared full detailed 

 instructions. In order to simplify this work as much as possible, a number 

 of problems which have been under investigation in previous years were 

 omitted for this year and the more important ones somewhat enlarged. 



Sex and Flower Color in Lychnis. — The studies in the inheritance of sex 

 and color-characters in Lychnis have been Dr. Shull's largest project of the 

 year. The results of the work with Lychnis are confirmatory of those 

 already published, and numerous crosses have been made to test certain new 

 phases of the subject. The attempt to secure a pure-bred purple-flowered 

 strain of Lychnis has again failed of attainment, owing to the fact that in 

 each cross made for this purpose one or the other parent proved to be hetero- 

 zygous. The effort is to be continued in order that material of definitely 

 known hereditary characters may be available for use in subsequent experi- 

 ments. As in previous generations, several new mutants of Lychnis having 

 hermaphrodite flowers have appeared this year, but they constitute an ex- 

 ceedingly small percentage of the individuals grown. The crosses in which 

 hermaphrodites were used as the male parents have again been found to 

 result in progenies in which the male members are hermaphrodites. Normal 

 male mutants also appear rarely in these families. True males may occa- 



