ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 301 



Plusia gemma. In the oocyte of the first order, the chromatin of the 

 nucleus is separated from the nucleolus ; the nucleolus passes to one of 

 the first four blastomeres, and thence onwards ; the maturation is 

 identical in the parthenogenetic and fertilised ova, two polar bodies 

 being formed. The first polar body divides into two : these unite with 

 one another and with the second polar body, to form a " polar nucleus," 

 which multiplies by mitosis, giving rise to numerous nuclei immersed in 

 the polar ooplasm. About a half, or a third, of the ovum remains un- 

 divided, and forms an envelope for the embryonic cells. 



There is poly-embryony, for each egg gives rise to about a thousand 

 sexual larva?, and a hundred asexual larvae. The former become adults ; 

 the others, which are very rudimentary, perish. Each embryo is sur- 

 rounded by a double envelope, partly due to the ooplasm and polar 

 nuclei, and partly to a stratum of cells, delaminated off from the em- 

 bryonic morula. The female pronucleus is capable of developing of 

 itself and giving origin to males only. The fertilised ova develop into 

 females. 



Stomach of Wood-Bee.* — E. Bugnion gives a detailed account of 

 the stomach of Xylocopa violacea, and compares it with that of the hive- 

 bee, the humble-bee, and the wasp. 



Palaearctic Bassides.f — Claude Morley has revised the Ichneu- 

 monidous group Tryphonides schizodonti, of which he gives a tabular 

 synopsis, together with notes on the synonymy, economy, and distribu- 

 tion in Britain, as well as descriptions of new species. The palaearctic 

 fauna now includes more than sixty species. 



Artificial Parthenogenesis in Ova of Silk Moth.J — E. Quajat has 

 continued the experiments of Tichomiroff and Yerson. He found that 

 when unfertilised ova were subjected to various kinds of stimuli — 

 oxygen, increased temperature, sulphuric acid, hydrochloric acid, carbon 

 dioxide, and electricity — development was induced in many cases, and 

 sometimes continued till a larva was formed. Some ova were unaffected 

 and died, and some unstimulated, unfertilised ova showed beginnings of 

 development. The author proposes to continue the experiments, and to 

 make them more precise. 



Lepidoptera of Morocco. § — E. G. B. Meade-Waldo gives an account 

 of Lepidoptera collected in extensive journeys in Morocco. Special 

 attention was given to high mountain species. An analysis of the list 

 shows how very few species there are in these remote regions that are not 

 also to be found in the Mediterranean region, and that these mountains 

 have developed comparatively few Alpine species. 



Number of Facets in Beetles' Eyes.|| — K. Leinemann has had the 

 patience to count the number of facets in the eyes of 150 species of 



* MT. Schweiz. Entomol. Ges., xi. (1905) pp. 109-28 (4 pis.). 



t Trans. Entomol. Soc. London (1905) pp. 419-38. 



% Atti R. Accad. Sci. Padova, xxi. (1905) No. 3, 16 pp. See also Zool. Zentrabl., 

 xiii. (1906) pp. 108-9. 



§ Trans. Entomol. Soc. London, 1905, pp. 369-93 (2 pis.). 



11 Dissertativ. Miinchen., 1904, 64 pp. See also Zool. Zentralbl., xiii. (1906) 

 pp. 191-2. 



