I02 REPORTS ON INVESTIGATIONS AND PROJECTS. 



The colors of thorax, abdomen, and elytra were so strikingly differ- 

 ent in the two species that they seemed to be favorable material for 

 hj^bridization. Before going into the detailed study of the germ glands 

 of the two species, it seemed advisable first to determine the fertility 

 of the supposed hybrid eggs. Several generations of each species 

 were first bred true, to be certain of parentage, and twelve or fifteen 

 pairs of adults were hybridized reciprocally. They mated freely, and 

 thousands of eggs were deposited , but no larvce hatched . Control pai rs 

 of straight matings of each species were kept under observation at the 

 same time, and while it was noted that fewer eggs were deposited than 

 by the first generation, and a smaller percentage of eggs hatched, large 

 numbers of larvae were continuall}- hatching and feeding. The exper- 

 iment was abandoned for the present .season, but will probably be 

 undertaken by Mr. Lutz or myself on a larger scale next siimmer. 



REPORT OF ROvSWELI. H. JOHNSON. 



Since my work at the station began July iS, (905, this report must 

 be one of progress rather than results. Owing to the lack of running 

 salt water, I have postponed the proposed work upon the shrimp and 

 devoted myself wholly to the investigation of the lad}' beetles. These 

 beetles offer the following advantages as material for the study of the 

 method of evolution : 



1. The}' are in general decidedly variable in color pattern in each 

 locality, and in many species show geographical races. 



2. There are man}^ "varieties" in some species, ranging from 

 mere ' ' aberrations ' ' to forms over which systematists are in disagree- 

 ment as to their recognition as species. 



3. There are some species whose relationships .seem evident and 

 which have doubtless only relatively recently become segregated. 



4. Some species, I have found, are readily modified by change in 

 environment. 



5. The generations are short, and some species at least may be bred 

 under glass in winter. 



6. Being easil}' recognized and collected by correspondents, exten- 

 sive collections are possible. This is e.specially true of some species 

 which are gregarious. 



Since they may be fed upon plant-lice or .scale insects, I began a 

 collection and catalogue of the local aphids and determined the best 

 host-plants for use indoors and in the garden. The most suitable 

 plants have been propagated in the breeding-room, that there may be 

 an adequate supply of food when the aphids out of doors disappear for 

 the season. I am now feeding many pairs from California, the Rocky 



