RILEY ANISOPTERYX VS. PALEACRITA. 573 



less mistook, under his microscope, the hairs of the moth. The 

 article closes with the following : 



Fertilization of plants exclusively by insects is, to my knowledge, not 

 yet positively proven ; but intentional fertilization, if one should take this 

 for such, would belong to the realm of fable. This moth, in my opinion, 

 is no Pronuba, but a corruptrix. 



Mr. Boll should increase his knowledge by perusing what has 

 been written on the fertilization of flowers by insects. He should 

 also learn something more than he has done in this instance of a 

 subject he intends to treat, and especially of observations which 

 he undertakes to criticize. Investigations, however instigated, 

 should be carried on, not under the warping influence of indi- 

 vidual motive, but solely for the love of truth and knowledge. 



On the Differences between Anisopteryx pometaria, 

 Harr. and Anisopteryx ^scularia, W.-V., with 

 Remarks on the Genus Paleacrita. 

 By Charles V. Riley. 

 [Read Nov. 5, 1S77.J 



Through profound study alone can we arrive at the true rela- 

 tionships of animals, especially in the inferior classes. Among 

 insects, dozens of species in some families are absolutely undis- 

 tinguishable in the imago state, though differing widely in the 

 adolescent stages and in habit ; while others, again, vary to such 

 a degree that the same species has been described under more 

 than a dozen names, and not unfrequently been made the basis 

 of different genera. The Canker-worms furnish good occasion 

 for these remarks. In the previous communication to the Acade- 

 my on these insects, I stated (p. 27S) that Anisopteryx pometaria 

 differed from the other species of the genus, so far as was then 

 known, in having an additional pair of prolegs in the larva state, 

 but added: "For the present I deem it best to refer it to Aniso- 

 pteryx, as more careful study will probably show that in the char- 

 acters of egg, larva, and chrysalis, the European species of the 

 genus agree with it, and that some of the structural features of 

 the adolescent states have been overlooked in Europe, as they so 



