BIOLOGY, EXPERIMENTAL — DAVENPORT. 1 03 



Mountains, and New York, awaiting further egg-laying, and have 

 already 18 fraternities of larvae from these pairs. The larvae require 

 from two weeks to a month from egg to pupa. About five days are 

 required for the eg^ and pupa stage, respectively. 



The questions to be answered by the earlier generations are : 



1 . To what extent are the various color patterns inheritable ? and 



2. Does rearing under local and indoor conditions modify them 

 from the ancestral pattern ? 



With these questions answered I shall undertake hybridization, 

 selection, and modification experiments. 



Since many larvae of one species could be collected this summer, I 

 began a series of experiments upon modification by various changes 

 in the environment. Some factors seemed relatively impotent, but 

 temperature was effective in producing marked changes paralleling 

 observed geographical races. These changes affected certain parts 

 of the pattern only, thus producing more than a change in the 

 amount of melanism. 



Before taking up my work here I had collected large series of one 

 species, Hippodaniia convergens, from diverse regions, and I am now 

 extending that collection by excliange and purchase. I find that 

 some alleged species are connected by many intergrades, as might be 

 expected. The various lines of orthogenetic variation in the differ- 

 ent regions seems more remarkable. As a proper introduction to my 

 experimental results in Hippodaniia, I propose to submit in April a 

 paper on " Orthogenetic variation in Hippodamia convergens.'' 



REPORT OF DR. W. J. MOENKHAUS. 

 During the summer of 1 904 material was collected at Woods Hole 

 and Cold Spring Harbor for the study of the behavior of the mater- 

 nal and paternal chromosomes in hj'^brid fishes. Early stages of the 

 following crosses were preserved : 



1. Funclulus heteroclitus X F. diaphauus. 



2. Fundulus heteroclitus X F. majalis. 



3. Fundulus heteroclitus X Tautogolabrus adspersus. 



4. Fundulus heteroclitus X Stenotonius chrysops. 



5. Fiindulus heteroclitus X Gasterosteus bispinosus. 



Crosses 2 and 5 have been worked up without results ; 3 and 4 

 have not yet been studied, but I am hopeful that they may yield 

 some important thing in the chromosomal behavior in early hybrid 

 development. 



Considerable work was done with the crosses between Fiindtdzis 

 heteroclitus and Fujidubis diaphayius. In the cytological work on 

 these I had the cooperation of Miss Anne M. L,utz. It was hoped 



