IN THE GENUS BASILARCHIA 25 



again, that most insect eggs are laid on the 

 broader parts of the leaf on which the young will 

 feed ; it is here that the parasite will range in 

 quest of prey ; but the eggs of Basilarchia are 

 rarely found except at the extreme tips of leaves, 

 and in addition the leaves of the food-plants con- 

 cerned are all acuminate, some to an excessive ex- 

 tent, as in some of the poplars and birches. When 

 the parasite has, however, found an ^gg^ it may well 

 be inquired whether she would not be deceived by 

 it. It differs from the eggs of all our other butter- 

 flies in that it is besprinkled with little flexible fila- 

 ments, for all the world like the hairs of some leaves. 

 Or if the clothing of the eggs did not deceive, she 

 might even then find it difficult of attack, for 

 minute as these parasites are, less than half a milli- 

 metre long, their bodies would extend across at 

 least three of the polygonal cells which regularly 

 stud the surface of the Qgg^ and which send forth 

 these little filaments at every angle, so that poor 

 bewildered Madame must struggle through a weary 

 chaparral before she can attain the barren grounds 

 at the summit and find a spot to readily insert 

 her sting. Yet that she succeeds is only too evi- 

 dent to the collector ; the larger part of the eggs 

 obtained in the open field which have fallen into my 

 hands have been parasitized. 



