Miscellaneous. 79 



Lachnidium acridiorurriy Giard — we ascertained that the repeated 

 moults of these insects, which take place on an average once a 

 week, are opposed to the fixation of the spores upon the integu- 

 ments *. On the other hand, if we consider that it is often the 

 stigmatic apertures that, in the adults, serve as a means of penetra- 

 tion for the spores, and if we remember that, after the spores have 

 germinated, the ramifications of a thick mycelium block up the 

 tracheal trunks, producing the phenomena of asphyxia t, we are 

 obliged to recognize tliat, in the case of young Acridians, the casting 

 off, with the integament, of the internal coat of the trachesB is a 

 serious obstacle to the preservation of the spores in the medium 

 suitable for their germination. 



In the course of the mission that we are accomplishing under the 

 government of the Argentine Republic, we have been enabled to 

 make observations which give a larger bearing to these preliminary 

 remarks. 



In drawing attention to the role of the pigments in the pheno- 

 mena of histolysis and histogeny which accompany metamorphosis 

 in the case of the migratory locust (Schistocerca ^^eregrina, Olivier) J, 

 we showed that after each ecdysis these Acridians excreted pig- 

 mentary matter with the faeces, which were thus found to be 

 coloured pink, instead of remaining greenish brown as in the course 

 of each of the stages of their development. In following very 

 closely the development of the Parana locust (Schistocerca para- 

 nensis, Burmeister), in order to see if we could not discover some 

 peculiarity that might have escaped us, we have been led to examine 

 the first excreta after the completion of metamorphosis ; the result 

 was that it was discovered that the faeces, like those of the African 

 species, were charged with red pigmentary granulations. But this 

 time, on pushing the analysis further, the microscopical examination 

 showed us that these excreta were in reality a kind of sacs formed 

 by the cuticle of the intestine. These sacs, immediately after 

 being deposited, on being immersed in distilled water exhibited the 

 most interesting peculiarities ; from the very first they were seen to 

 be inflated by large bubbles of air, which maintained them in 

 suspension ; these bubbles were nothing else than the remains of 



* J. Kiinckel d'Herculais and Ch. Langlois, " Les Champignons para- 

 sites des Acridiens " (C. R. de la Soc. de Biol. 9° s^r. t. iii. p. 490, June 20, 



1891 ; ' Comptes Rendus,' t. cxiii. p. 1465, June 22, 1891 ; Ann. de la 

 Soc. ent. de Fr. t. Ixi., 1891 ; Bull. t. cvi., June 24). 



t A. Giard, " Observations sur les Champignons parasites de VAcri- 

 dium peregrinum " (C. R. de la Soc. Biol. 9" ser. t. iii. p. 492, June 20, 

 1891) ; A. Giard, " Nouvelles iltudes sur le Lachnidium acridiorum, Giard, 

 Champignon parasite duCriquet pelerin" (Rev. gdn. de Bot. t. iv. pp. 459, 

 460, 1892). 



X J . Kiinckel d'Herculais, " Le Criquet pelerin, Schistocerca ^peregrina, 

 Olivier, et ses changements de Coloration. Role des Pigments dans les 

 Ph^nomenes d'Histolyse et d'Histog6nese qui accompagnent la Mt^tamor- 

 phose " (Comptes rendus de la Societe de Biulogie, 9^ st^rie, t. iv. p. 56, 



1892 ; Comptes Rendus, t. cxiv. p. 240, February 1, 1892 ; Annales de 

 la Society entomologique de France, t. Ixii. Bulletin, p. 25, 1802). 



