ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 269 



Blastophaga psenes of the Fig. — G. Grandi {Boll. Lab. Zool., 

 Scuola Agric. Portici., 1920, 14, 63-204, 31 figs.). A detailed descrip- 

 tion of the structure of this Chalcid insect concerned in the caprification 

 of the fig. Both sexes are dealt with and the ova, larvae and pupie. 

 An account is given of the behaviour of the insects, the sex-relations, 

 the life-history, and the year's life. J. A. T. 



Tracheal Air in Dragon-fly Larvae. — -Hans Wallexgren (Lunds 

 Universitets Arsskrift, 1915, 11, No. 5, 1-12). In larval dragon-flies 

 (Aeschna), breathing normally, the oxygen-content of the tracheal air is 

 always lower, and the COa-content the same as or a little higher than 

 that of the respiratory water. There is no reason to postulate any 

 special cellular activity. Diffusion explains adequately what takes 

 place. The composition of the tracheal air is directly dependent on 

 that of the surrounding water, but has a lower 0-content. From the 

 tracheal gills the oxygen diffuses into the large dorsal and ventral 

 tracheag. By the breathing movements, the body-movements, and the 

 contractions of the wall of the respiratory gut, as well as by diffusion, 

 the oxygen passes into the finer tracheal branches and is absorbed by 

 the blood, the tissue fluid, and the cells themselves. The COo given 

 off by the cells passes into the tissue fluid and the blood, but passes 

 only to a slight extent into the tracheal system. It diffuses from the 

 blood into the water through the body-wall, the tracheal gills, and the 

 wall of the respiratory gut. When the oxygen of the water sinks 

 2"5 c.cm. per litre, and the larvEe are in respiratory diificulties, they 

 ascend to the surface, where they take in oxygen to a degree far above 

 that in the ordinary tracheal air in sub-aquatic conditions. When it is 

 about 12 p.c. higher than the sub-aquatic normal the insects descend 

 again. J. A. T. 



Larva of Rhinocypha ignipennis. — F. C. Fraser (diem. Dep. 

 Agric. India, 1920, 7, 13-4, 1 pi.). A single specimen of the larva of 

 a dragon-fly common in the rivulets about Shillong. The legs are of 

 great length, slim and spidery, adapted for clinging to weeds or roots. 

 The larva has no caudal gills, and it is not likely that they were lost. 

 Both Rhinocypha and Micromerus are thus apparently purely procto- 

 branchiate : the caudal gills being only rudimentary in the latter. It 

 is not known where the young insects hide themselves, for every con- 

 ceivable place was searched and only one was found. The larva is 

 interesting systematically in confirming the view that the Libellaginse 

 should form a distinct sub-family. J. A. T. 



Rice Leaf-hoppers. — C. S. Misra {Mem. Dept. Agric. India, 1920, 

 5, 207-39, 4 pis., 9 figs.). These pests, Nephotettix bipunctatus and 

 A^ apicalis, recently did great damage in the Central Provinces, blight- 

 ing the rice-fields. Prior to 1913 nothing was known of them as 

 agriculturally important. Till then they were known as the " green- 

 flies " of cities like Calcutta, where they swarm in thousands around 

 the electric lamps in the streets as well as the bare lights in houses. 

 They illustrate insects which are considered harmless for a time, but 



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