30 SUMMARY OF CURRENT RESEARCHES RELATING TO 



nerve joins that from the accessory eyes almost immediately. The 

 stages in the development may be outlined as follows : The earliest 

 primordia of the eyes are to be seen in the second nymphal period, when, 

 through a proliferation and elongation of the hypodermis, two groups 

 of cells are formed, one on each side of the mid-ventral line of the head, 

 and also behind each of the antennae on the dorso-lateral surface. By 

 the third stage the areas on the ventral surface have increased sufficiently 

 to meet, and the cells of the original groups protrude farther. The 

 visual rods then appear. They grow out from the distal end of the cells. 

 At practically the same time nerve-fibrils appear at the proximal end of 

 these cells. After this the cells so far concerned sink below the adjoin- 

 ing hypodermis. In the earlier part of the fourth stage this hypodermis 

 undergoes a change, and, pushing in from all sides, becomes super- 

 imposed on the visual rods, and forms the corneal hypodermis and the 

 iris. These then secrete the lens. The depositing of the pigment keeps 

 pace with the development of the lens. 



Study of Puss Moth.* — G. Martelli has studied the habits and life- 

 history of Dicranura vinula, and discusses their nocturnal activity, the 

 death of the male after a first or at most a second copulation (which 

 may last 12 hours), the oviposition, the four larval moults. As to 

 parasites, it is noted that Eiicyrtus vinulse and Eupelmus sp. attack 

 the eggs and Paniscus testaceus the larvae. 



Vitellus in Silkmoth's Eggs.f — C. Vaney and A. Conte have traced 

 the history of the vitelline globules that appear in the ovum about two 

 hours after laying. Before the differentiation of a blastoderm the 

 developing egg is a syncytium. This gives place to defined cells — 

 some formative and others vitelline. A chromidial plexus around a 

 number of vitelline globules becomes the centre of a vitelline cell. The 

 vitelline cells are more than passive sacs ; are not digested by the intes- 

 tinal epithelium ; their protoplasmic part absorbs the vitelline globules, 

 and a nutritive fluid passes into the embryo by osmosis. 



Intestinal Secretion in Deilephila.f — Deegener gives a detailed 

 account of the process of intestinal secretion in caterpillars of Deilephila 

 euphorbise, describing seventeen stages. 



Abdominal Sensory Organ in Noctuida3.§ — P. Deegener describes 

 n new organ on the first segment of the abdomen in Pseudophia lu/iaris, 

 Plusia gamma, etc. A duct leads into a cavity with ridges of sensory 

 setae. The function is probably auditory. 



Development of Mid-gut in a Beetle. || — Jan Hirschler has studied 

 the formation of the germinal layers and of the gut in Gastroidea 

 viridula Deg. One of his general results is that the mid-gut has a 

 multipolar origin. It is formed from two endodermic hoop-like 

 primordia and several endoderm islands. It is wholly an endodermic 

 product. 



* Boll. Lab. Zool. Scuola Agric. Portici, iii. (1909) pp. 239-GO (12 figs.). 



t C.R. Soc. Biol. Paris, lxviii. (1909) pp. 87-8. 



% Arch. Natur., lxxv. (1909) pp. 71-110 (1 pi.). 



§ Zool. Jahrb., xxvii. (1909) pp. 031-50 (1 pi. and 1 fig.). 



|| Bull. Acad. Sci. Cracovie, 1909, pp. 284-308 (1 pi. and 2 figs.). 



