OF WASHINGTON. 259 



the egg-body reaches the perforation, the ovipositor is partially 

 withdrawn and the whole egg then pushed in till the egg-body 

 reaches the bottom. Adler rightly expresses wonder that this 

 complex procedure should be repeated so often with such great 

 accuracy, and proceeds to describe the tactile hairs connected 

 with the ovipositor which permit her to carry out the operation. 

 He further states that while oviposition on the surface of leaves 

 is, in its nature, easier, the mechanism of oviposition is exactly 

 the same as that in buds. 



As already stated, the observations are difficult and can only 

 be made with satisfaction by observing a great number of indi 

 viduals and by suddenly chloroforming them at different stages of 

 the operation. Adler has done this to some extent, but there are 

 several passages which leave some doubt in my mind as to the 

 complete accuracy of his views. For instance, in controverting 

 Hartig and referring to his (Adler's) figures of the eggs and of 

 the ovipositor, there is no indication as to whether the eggs were 

 taken from the buds afterbeing deposited, or from the ovaries or 

 from the ovipositor. My own experience with these and other 

 ductile and extensile eggs with long egg-stalks would indicate 

 that we have a very varying length of stalk according to these 

 varying circumstances. Therefore, it is rather inaccurate to re 

 fer to these eggs as if they had a definite and uniform length as 

 compared with the ovipositor. Moreover, the passages quoted 

 show that the operation varies considerably in different species, 

 his conclusions evidently being based on Neuroterus Icevius- 

 culus. 



Again, any one who will carefully read Hartig will see that 

 Adler has totally misjudged him in assuming that he described 

 the egg as passing down the minute channel of the seta ; for 

 Hartig's language, as well as his figures, makes it very plain that 

 he had in mind the actual facts, viz., the passing of the egg down 

 the channel formed by the connection of the two spiculae with 

 the seta. It is true that he calls the seta the egg-guide {Eileiter), 

 and this in truth it is, but he distinctly shows by his figure and 

 his description that it acts as a guide only by the passage which 

 it makes when mortised into the spiculae, referring particularly 

 to this space (Tab. i, Fig. 9, c) as "die innere Hohlung des 

 Legestachels, in welche das Ei aufgenommen und hindurch 

 geht."* 



* Incidentally I may state, as corroborative of Adler's liability to error, 

 that he makes the sweeping assertion that the gall-gnats (Cecidomyidae) 

 cannot inject an irritating poison into the plant tissue as do the saw-flies 

 (Tenthredinidae), on the ground that the gall-gnats have no piercing ap 

 paratus. He is in good company in making this statement, but I have good 



