62 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tubes ; each follicle has the form of an elongated saccule, formed by 

 a structureless membrana propria and the seminal elements. The 

 similarity in number confirms the view that the testicular and ovarian 

 tubes are homologous; their general arrangement indicates their 

 affinity with the Phryganidee. 



As to the external male organs, for which the author laments the 

 absence of a suitable terminology, he states that the eighth abdominal 

 segment is conical, and has its tip directed backwards ; dissection 

 is necessary to reveal the ninth segment, which is circular in form, 

 and has the dorsal much smaller than the ventral half; the penis 

 appears to be the chitinized end of the vas ejaculatorium, and forms 

 a fine tube, which is invested by a thin prseputium, and has a soft 

 enlargement at its end — this may be called the balanus ; at the hinder 

 end of the ninth segment there are two valvular appendages, and with 

 these a small chitinous ring is connected dorsally ; the anal orifice is 

 within this ring. 



The study of this small lepidopterous insect leads to points which 

 seem to be important in the morphology of the Insecta; in their 

 organization the Lepidoptera exhibit some very primitive characters 

 — for example, they sometimes have ten abdominal segments ; in 

 N. metallicus there are a large number of seminal follicles, and this 

 must be reckoned a primitive arrangement. The author thinks that 

 the possession of only two Malpighian vessels in some butterflies is 

 very remarkable, and says that it suggests to him a theory of periodic 

 atavism which he will develope more fully in a future work. 



He suggests that the embryology of the " Microlepidoptera " should 

 be investigated, as the system of this group (as its name alone is 

 sufficient to show) requires to be thoroughly revised. 



Development of the Flea's "Egg* — Mr. M. H. Eobson describes 

 some stages in the development after completion of segmentation. 

 The egg being transparent, its development is easily followed : from 

 three to twenty-four eggs are laid separately by a female. Thirty-six 

 hours after laying, the blastoderm occupies one-third the circumference 

 of the egg, by the fourth day the embryo has absorbed the yolk and 

 nearly fills the egg. It hatches on the sixth day. When hatched, 

 the larva is destitute of appendages, except a pair of small antennsa 

 and a pair of mandibles, and resembling many other insect larvae. 

 After eight days the larva spins a fluffy cocoon, from which the 

 young flea emerges in nine days. 



Development of Epicauta verticalis.| — M. H. Beauregard has 

 examined the life-history of this vesicating insect with the object of 

 seeing whether, like the American species described by Eiley, it is 

 parasitic in the nests of Acrididse ; placed with a nest of jSEdipoda 

 (/??, ceeruleus, and JE. germanica), on August the 28th, it increased in 

 size, and on October the 15th was in pseudochrysalis stage, which is 

 the hibernating form of all the vesicating insects. On the other 

 hand, efforts to rear the larvae on honey were fruitless, and it became 



* Sci.-Gossip, 1885, pp. 252-4 (7 figs.), 

 t Comptos Kendus, ci. (1885) pp. 754-6, 



