262 THE ENTOMOLOGIST. 



ornithologists may be excused for hesitating to accept, seeing 

 how very brittle are the eggs to which they have devoted 

 their best attention. This faculty of growth in the egg-state 

 vras known to Linnaeus, and has been recorded by all subse- 

 quent writers on this tribe of insects. To criticise or contra- 

 dict observers so careful as Professor Peck and Dr. Harris is 

 out of the question ; but there is one point in which I differ 

 from these most observant and accurate entomologists. Both 

 Peck and Harris either state, or lead us to infer, that the egg 

 is laid and that the larva feeds on the under side of the leaf. 

 My own experience is exactly the reverse of this, and agrees 

 with that of the Rev. Charles Bethune, as given at p. 51 of 

 his 'Annual Report of the Entomological Society of Ontario,' 

 which I have lately received through the courtesy of my kind 

 friend Mr. Reeks, of Thruxton. My experience agrees with 

 Mr. Bethune's ; 1 find the larvae on the upper side of the leaf. 

 This want of accord may probably arise from there being 

 several species confounded under one name, and three of 

 them 1 had named provisionally after the trees on which I 

 found the slug feeding: — Blennocarapa Cerasi on the cherry, 

 B. Pruni on the plum or sloe, and B. Pyri on the pear. I 

 find, however, that I am unable to differentiate these in a 

 manner likely to find acceptance with entomologists. I 

 therefore prefer adopting "^thiops" as a specific name for 

 all our slug-worms, at the same time expressing a feeling of 

 some regret that the word " nigger," the literal translation of 

 ^thiops, should have been applied to the sawfly of the 

 turnip, — a very different insect, and one of which a complete 

 life-history has already been given in the ' Entomologist.' 

 Another question of some interest, as regards the geographical 

 distribution of insects, arises as to the identity of the slug- 

 worms of Europe and America. There is, however, no 

 necessity to introduce this difficulty to the reader, unless it be 

 to say that the three are so similar that I am unable to 

 separate them. 



To proceed with our life-history of the one which feeds on 

 the pear-tree. The eggs continue to grow during thirteen days; 

 at first slowly, towards the end of that period more rapidly. 

 On the fourteenth day, according to Professor Peck, the 

 young grub emerges fiom the egg. I have no doubt this 

 statement is correct as regards the United States, but I 



