92 THE CANADIAN ENTOMOLOGIST. 



with Neuroterus fumipennis. The second part (2.\ pg.) was published 

 three months later than Mr. Cameron's paper, which contains, neverthe- 

 less, some of the names of the species (5 out ol 7) treated in the second 

 part, probably out of a provisionally published notice, unknown to me. 



Dr. Adler having raised in 1874 out of all Neuroterus fumipennis galls 

 nothing but Spat/iegaster albipcs, decided to observe them more exactly. 

 The experiments with Neuroterus J urn ipennis were made in 1875 in the 

 following manner : 



The galls were collected in the autumn before. When the wasps began 

 to appear, they were put on a small oak tree in a tub in a cool 

 room. When a wasp began oviposition each twig was enclosed in a 

 glass tube, after the bud had been marked with a thread. There were 

 marked March 14th — 12 buds, March 19th — 10 buds, March 24th — 8 

 buds, March 26th — 6 buds ; in all, 36 buds. Besides those, other wasps 

 were put on cut oak twigs placed in damp earth or sand (in which manner 

 the twigs keep well three weeks and longer as good material for observing 

 the eggs), and after oviposition was observed, the isolated twig was covered 

 with a glass bell. The wasps were examined after the oviposition and the 

 receptaculum seminis found to be empty. The receptaculum is in the 

 agamous species always somewhat atrophied ; in the bisexual species the 

 external membrane is pigmented, and even if empty, forms a ball. 



Besides those experiments, others were made at the same time in the 

 open air. The oviposition was observed March 31st on 5 buds, April 1st 

 on 7 buds, April 2nd on 12 buds, April 7th on 12 buds, April 10th on 

 40 buds, April 12th on 38 buds ; altogether on 114 buds. A curious fact 

 is related that in 42 buds the ovipositor of the wasp was found left in 

 the bud. 



The results of the different experiments were as follows : The small 

 oak tree in the tub was kept in the room and began to bud in the 

 beginning of May, and the leaves were developed enough May 14th to see 

 if galls were forming. Of the 36 marked buds, 13 had no galls pro- 

 duced ; on the others in all 36 galls were counted. It is to be remem- 

 bered that here oviposition was made and observed in the room, the twigs 

 carefully isolated by glass tubes, and kept in the room till the tree began 

 to bud. Therefore it is impossible that eggs could have been laid by 

 other wasps. The galls were those of Spath. albipes. Concerning the 

 experiments in the open air, the leaves of the tree were May 20th so far 



