I04 REPORTS ON INVKSTIGATIONS AND PROJECTS. 



When time was available from the breeding work, the variation and 

 geographical distribution of the genera used were investigated and my 

 own collection much enlarged. The collections in New York, Philadel- 

 phia, and Washington vvere studied. A lot of 15,415 Hippodamise from 

 the top of Kamiack Butte, Washington, was classified into categories 

 and the intermediates arranged. The distances between spots, the thick- 

 ness of the connections between spots when joined, and correlations of 

 a lot of 334 Hippodamias from Fairfield, Washington, were studied statis- 

 tically. These results, which were to have been published this pa,st 

 spring, I have decided to publish later with the experimental work. The 

 lady-beetles when disturbed exude from some joints of the legs a fluid 

 tasting like aloes. That this is really distasteful to birds I have found 

 by experiment. The spots upon the lady-beetles have been supposed to 

 be association marks by which the birds may avoid lady-beetles and the 

 beetles thus profit. But if this were true, variations from the pattern in 

 the directions of loss or fusion would be eliminated. Yet in most parts 

 of the United States the spotted Hippodamia convcrgens occurs along 

 with some of its forms or closely related species which show fusion of 

 spots, and in parts of California and Oregon with a form that is spotless. 

 In California, where the spotted and spotless forms are together, a num- 

 ber of mated pairs which I collected showed no evidence of preferential 

 or assortative mating. It would seem, therefore, that the evolution of 

 the color-pattern in these beetles is not the result of selection, but that 

 here we deal with evolution resulting from progressive variation or from 

 mutation associated with dominance and imperfect segregation. The 

 fact that Coccinella fransvcrso-guttata, C. trifasciata, and Hippodamia con- 

 vergens all have their spotless forms in the same locality would make it 

 appear that the origin of the new forms is the result of direct alteration 

 of the germ-plasm by the environment in these cases. These beetles there- 

 fore seem to be in the very condition which most needs investigation. 



An incidental result of my hunt for aphids has been the discovery of 

 some on plants which do not seem to be recorded as hosts. This with 

 information as to the preferences shown by some lady-beetles for some 

 aphids and distaste for others and as to the parasites of lady-beetles may 

 be of use to economic entomologists and will be published separately 

 where accessible to them. 



The following statistics give some idea of the extent of work done: 



Controlled inatings 205 



Of these, fertile eggs obtained from 22 



Number of females isolated (from the field) 74 



Fertile eggs obtained from 49 



Progeny reared successfully 49° 



Pupae brought in from field for modification experiments and emerged. 74 



Pupae collected in field for observation, emerged ii7 



Larvae now developing 72> 



