126 EEVIEWS. 



be produced. If the wound made by the needle be too deep, or the 

 drop of ammonia too large, the victim really dies, as is speedily pro^'ed 

 by its decomposition. If, on the contrary, the puncture be too slight, 

 the insect recovers, after a shorter or longer period of profound 

 lethargy, and regains, at any rate partially, its pristine vigom'. On 

 those Coleoptera, the thoracic medullary centres of which are distant 

 from each other, the effect produced by ammonia is very different. 

 A wound which would have completely and permanently stumied a 

 vigorous Scaraboeus sacer causes only violent convulsions in a Carabus 

 of moderate size. Gradually the insect becomes calm, and slowly 

 regains its original condition. If the experiment be repeated several 

 times on the same individual the same results ensue, until the wound 

 becomes too severe, and the poor animal expires. Melasomas and 

 Longicorns are more sensitive. The corrosive liquid plimges them 

 instantly into a stupor, which is however only temporary ; and the 

 next day they are lively as ever. Thus, by the process so perfectly 

 successful in the case of Scarabtei, Curculionidae, and Buprestes, it 

 is impossible to produce the same state of paralysis in those Cole- 

 optera of which the three thoracic ganglia are situated at a distance 

 from each other, 



M. Tab re's second paper is as interesting as the first : it relates to 

 the habits and metamorphoses of the Sphex in general, and of Sphex 

 Jlavipennis in particular. He opens the subject in his own inimitable 

 style, with a beautiful description of insect hfe, an abridgment of 

 which would give no adequate idea of the richuess of colouring, and 

 felicitous arrangement of epithets which invest all the writings of this 

 author with a peculiar charm. 



Towards the end of July, the Sphex Jlavipennis, tearing open the 

 cocoon which has hitherto enveloped her, takes flight from her subter- 

 ranean abode: and during the month of August she may be observed, 

 enjoying her brief holiday, flying gaily from plant to plant, and basking 

 in the bright rays of the summer sun. But the preservation of her race 

 exacts from her the sacrifice of the few remaining days of her short 

 life, and from the beginning of September she devotes herself to la- 

 bour for the good of her posterity. She is not more fastidious than 

 the Cerceris in the choice of a site for her operations : a loose sandy 

 soil and plenty of sun being the only desiderata. She takes no pre- 

 cautions for sheltering her work during its progress, and it is pitiable to 

 observe the destruction often caused by a shower of rain, by which many 

 a half-finished nest is washed into a heap of imdistinguishable ruins. 



The Sphex Jlavipennis rarely works alone : from ten to twenty 

 individuals generally combine to excavate a gallery; accompanying 

 their labours with a species of song, sharp and intermittent, modula- 

 ted by the vibration of their wings and body. A keen enjoyment of 

 their task seems to animate these little sappers and miners : they 

 spring here and there with delighted activity, and in the course of a 

 few hours a gallery is completed. AVheu examined it is Ibimd to con- 

 sist of a horizontal corridor, serving as an a\enue to the hidden cells 



