404 SUMMARY OF CURRENT RESEARCHES RELATING TO 



pogon g.n., Macropeza, Isoplastus, Procladius, Tanypw, Chironomus, 

 Tanytarsus, and Gonocladius g.n. 



Chromidia in Cells of Muscidse.* — M. Popoff has studied the for- 

 mation of chromidia by the nucleus in the cytoplasm of fat cells, oenocytes, 

 and pericardia] cells in Muscidae. They correspond to ergastoplasm, mito- 

 chondria, chondriomites, chondriokonts, pseudochromoses, and "neben- 

 kern *' in glandular cells and sex-cells. The distribution of the chromidia 

 in the cytoplasm has a definite relation to function, e.g. to diffusion- 

 currents. As regards chromidia, there is a close resemblance between 

 the processes of glandular secretion and those associated with the 

 accumulation of reserves in germ-cells. 



Digestion in Wood-eating Caterpillars. f — P. Portier has studied 

 the curious larva of Nonagria typhse, \\hich bores in the stem of Typha 

 latifolia. The glandular area in the intestine is very restricted, and no 

 ferment capable of dissolving cellulose could be found. But there are 

 very abundant fusiform "pseudo-bacteria," probably minute moulds, 

 which work at the vegetable tissue, pass through the walls of the gut, 

 and are engulfed by leucocytes. In short, the micro-organisms which 

 break down the woody tissue form the main food of the caterpillar. 



Acephalous Lepidoptera.J — A. Conte and 0. Vaney ligatured cater- 

 pillars (of Bonibyx mori, C'heloma caja, and Lymantria dispar) at the 

 junction of head and thorax, and after the head was dry cut it off. The 

 caterpillars did not seem much affected by the decapitation, but they 

 moved more slowly. Chrysalids were formed, but only in the case of 

 L. dispar was an imago developed. It was normal except in the absence 

 of a head. This shows that the cephalic ganglia are not necessary for 

 the normal development of the trunk. 



Grape Moths. § — Schwangart gives an account of the two Tortricidas 

 (Conchylis arribiguella Hiibn., and Polychrosis butrana Schiff), whose 

 caterpillars do so much damage in the vineyards. In the Pfalz in 1906 

 the loss was estimated at six millions of marks. He discusses the life- 

 history and habits, the natural enemies, the various chemical, mechanical 

 and physical modes of dealing with attacks, and in particular the infection 

 with a pathogenic mould, a species of Cordyceps. 



Photogenic Organs of Lampyridae.||— F. A. McDermott and 0. U-. 

 Crane have studied the structure of these organs in Phot in us pyralis, 

 P. consanguineus, and Photuris pennsylvankus, and find that it is practic- 

 ally the same in the three, and very similar to that previously described 

 in other Larnpyridae. There are two distinct layers, the inner one 

 white and opaque, and serving as a reflector (possibly also protective to 

 the insect itself), the outer one yellowish and translucent, and containing 

 the actual photogenic mechanism. The organs are penetrated by in- 

 numerable trachea ; these connect near the spiracle with the tracheae, 

 which supply other organs, and very closely resemble these ordinary 



* Festschrift Richard Hertwig, i. (1910) pp. 19-48 (3 pis. and 2 figs.). 



t C.R. Soc. Biol., lxx. (1911) pp. 702-4. 



X Comptes Rendus, clii. (1911) pp. 404-6. 



§ Festschrift Richard Hertwig, ii. (1910) pp. 4G3-534 (3 pis.). 



|| Amer. Nat., xlv. (1911) pp. 306-13 (2 figs.). 



