166 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Oogenesis in Dytiscus marginalis.* — P. Debaisieux finds that four 

 differential kineses succeed theoogonial kineses and give rise to an oocyte 

 with fifteen nutritive cells. The " chromatic mass, 1 ' which appears at 

 the first of the four differential kineses, is transmitted intact to the 

 oocyte. After the last differential division there is a true synapsis, before 

 " the great increase of the oocyte." The behaviour of the chromosomes 

 is fully described. 



Luminosity of Glow-worm. f — Fr. Weitlauer finds no warrant for 

 regarding the luminescence of Lampyris splendidula as bacterial. It is 

 an oxidation phenomenon, occurring mainly in the grains ofammouiacal 

 uric acid and diffused through the body, and in both sexes. Occasionally 

 the luminosity is absent in both sexes. 



Life-history of Agrionid Dragon-fly. J — P. Balfour-Browne deals 

 especially with Agrion palchellum and Ischnura elegans. While a pair 

 fly about or rest, attached per collem, the female curves her abdomen so 

 as to bring the underside of her 9th segment in contact with that of the 

 2nd abdominal segment of the male. Soon after the transference of 

 sperms the female begins to lay, the male usually holding her, though 

 remaining entirely passive. The observer followed Agrion and Ischnura 

 right through from the egg to the imago, and describes the stages marked 

 by the successive moults. He discusses the development of the form of 

 the nymph, and pays special attention to the pro-nymph stage. This 

 stage is apparently for the purpose of freeing a tightly-packed larva from 

 the egg. The amnion, instead of breaking and remaining within the 

 shell, continues intact until after the larva is clear. The amnion forms 

 the pro-nymph skin. 



The fact that certain moults have nothing whatever to do with 

 growth (e.g. of the pro-nymph) seems fatal to a theory that growth is the 

 cause of moult : while the fact that certain moults have apparently nothing 

 to do with development, seems fatal to a theory that makes development 

 the cause of the moult. Since, however, both causes seem to be at work, 

 it is possible that both theories, combined and readjusted, may give us a 

 true explanation of the significance of the moult. 



Irish Neuroptera.§ — J. J. F. X. King and J. N. Halbert have made a 

 new list of the Neuroptera of Ireland, including 240 species, in 105 

 genera — rather less than two-thirds of the number recorded for Great 

 Britain. They have added eight species of Planipennia (alder-flies, etc.), 

 eleven species of Trichoptera (caddis-flies), and some others. The nomen- 

 clature has been brought up to date, and emphasis is laid on cases of 

 interesting geographical distribution. 



Development of Endoderm in Mole-cricket. || — J. Nusbauni and 

 B. Fulinski have traced the development of the mid-gut in Ghryllotalpa 

 vulgaris, and compared this case with otheis. In the anterior region of 

 the blastoderm the primordium of the endoderm and, immediately in 



* La Cellule, xxv. (1909) pp. 207-29 (2 pis.). 



t Verh. Zool. Bot. Ges. Wien, lix. (1909) pp. 97-103. 



% Proc. Zool. Soc., 1909, pp. 253-85 (2 pis.). 



§ Proc. 11. Irish Acad., xxviii. Section B (1910) pp. 29-112. 



j| Zeitscbr. wiss. Zool., xciii. (1909) pp. 306-48 (2 pis. and 11 rigs.). 



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