306 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Scent-organs of Male Noctuidae.* — R. Stobbe describes the minute 

 structure of the scent-organs on the first and second abdominal pleura 

 of some male Noctuidas, in the sub-family Trifinte. The secretion of 

 scent-glands passes out by a canal and is diffused on tlie tips of peculiarly 

 modified hairs. These are rooted in a depression of the first segment, 

 and can. be expanded in stellate fashion by a special muscle. The whole 

 organ differs in some notable details from that of male Sphingidse. 



Silk-g-lands of Potato Caterpillar.f — L. Bordas describes the 

 highly developed silk-glands of the larva of Phthorimsea operculella, 

 paired folded tubes longer than the body. Various parts may be dis- 

 tinguished, namely, the glandular region, the excretory canal, the accessory 

 glands of Lyonet, and the terminal efferent duct. 



Parasite of Eggs of Vine-Moths. J— P. Marchal and J. Feytaud 

 found inside the newly-laid eggs of Cochylis and Endemis, two Micro- 

 lepidoptera very destructive in the vineyard, the pupa of Oophthora 

 semblidis — a Chalcidid Hymenopteron. This important counteractive 

 parasite is wholly oophagous ; it has been previously recorded in the 

 ova of other Lepidoptera. 



Metamorphosis of Muscles in Tineid8S.§ — Ada Hufnagel finds in 

 Hyponomeiitd padella that most of the larval muscles persist and are 

 transformed into imaginal muscles. The process of transformation, 

 which occurs in various ways, is described in detail. Small nuclei, 

 multiplying by mitosis, may be distinguished from the characteristic 

 larval nuclei, which are large and exhibit direct division. At the begin- 

 ning of metamorphosis the small nuclei migrate into the depth of the 

 muscle, become surrounded with cytoplasm, and form myoblasts. The 

 cross striping disappears, the fibrillation remains, the large nuclei de- 

 generate and become the prey of phagocytes, the myoblasts fuse with 

 the myoplasmic strands, and so on. Some muscles, e.g. of the head, dis- 

 appear entirely. They become homogeneous and fragment. The nuclei 

 which have multiplied by direct division tend to fuse, finally forming 

 compact masses of chromatin. The muscle-fragments are finally en- 

 gulfed by phagocytes. 



Rectal Glands of Lepidoptera. || — L. Bordas gives a histological 

 account of these. From the interior outwards they show a chitiuous 

 membrane or intima, a layer of cupuliform cells, a basal membrane or 

 propria, connective tissue and tracheal branches, circular muscles, 

 longitudinal muscles, and an external peritoneal investment. 



Pole-cells and Gonads in Chironomus.^ — Martin Hasper has shown 

 in a convincing way that the pole-cells, w'hich are extruded at the 4-cell 

 stage and afterwards re-enter the developing egg, are the primitive sex- 



* Zool. Jahrb., xxxii. (1912) pp. 493-532 (4 pis. and 5 figs.). 



+ Comptes Rendus, cliv. (1912) pp. 618-20. 



X Comptes Rendus, cliii. (1911) pp. 633-G (1 fig.). 



§ C.R. Soc. Biol , Ixxii. (1912) pp. 331-4 (5 figs ). 



ll Bull. Sec. Zool. France, xxxvii. (1912) pp. 12-14. 



\ Zool. Jahrb., xxxi. (1911j pp. 543-012 (3 pis. and 14 figs.). 



