HARDWICKE'S SCIENCE GOSSIP 



63 



Fig. 37. Piipiliu palinurus. 



Fig. 38. Butterfly at rest on a branch whose leaves it mimics (Kallimu paralekta). 



that would paralyze even 

 Mr. Wood's powers of 

 literary work. 



MICROSCOPY. 



DlATOMACE.E OF THE 



Carboniferous Era. — 

 Count E. Castracane, a 

 well - known microscopist, 

 and investigator of those 

 minute but exceedingly in- 

 teresting organisms, has 

 (says Der Naturforscher) 

 announced to the Accade- 

 mia Pontificia at Rome, that 

 he has been fortunate 

 enough to prove the exist- 

 ence of diatomaceee during 

 the Coal period. His first 

 object of investigation was 

 a piece of Lancashire coal, 

 which was pulverized and 

 then exposed to a white 

 heat. The decarbonized 

 dust is then treated with 

 nitric acid and chlorate of 

 potash in test tubes, and 

 washed clean with distilled 

 water, and then placed 

 under the microscope. The 

 riiatomacese found in this 

 coal belong, with the 

 exception of a Grammato- 

 phora, of a small Coscino- 

 discus, and of an Amphi- 

 pleura, entirely to fresh- 

 water genera and species, 

 such as the following: 

 Frcigillaria Harrisonii, Sm., 

 Epithemia gibbet, Ehbg., 

 Nitzschia curvula, Kz., 

 Cymbella scolica, Sm., 

 Synedra vitrea, Kz., Diatoma 

 vulgare, Bong. The pre- 

 sence of the marine forms, 

 which were present among 

 the very numerous fresh- 

 water diatoms, only in one 

 single specimen, appears to 

 prove that, at one time, 

 even sea-water found its 

 way among the vegetation 

 from which the coal under 

 investigation originated. 

 Resides this Lancashire coal, 

 Count Castracane investi- 



