188 THE AMEKICAN MONTHLY [Jul 



ally listed 58 species while I have noted species under 

 twelve genera, not in his list, and a number of species not 

 listed, under the genera comprising his list. Mr. Peticolas 

 gives the coup de grace to the deposit by stating that he 

 was somewhat astonished by the "extraordinary number 

 of species" that he had found in the puzzling deposit. 



Taking a retrospective glance, I might note, that it was 

 in the year 1878, that by casually finding a copy of "Bail- 

 ey's Microscopical Observations, made while on a Trip to 

 the South," that the writer became inoculated with the dia- 

 tom infatuation if it be such, and through a double de- 

 cade has followed the study faithfully under the guise of 

 Micro-geology. I now have the impulse to inscribe herein 

 coronat opus est ; leaving as a hint to those who may de- 

 sire to tread a like path : Secure a type plate preparation 

 of this new deposit from whatever source it may be secur- 

 ed, and with the aid of the modern, perfected, oil homo- 

 geneous, and apochromatics, endeavor to work out from 

 the same, following in the footsteps of Nelson, Smith, 

 Cox and others the secondary and tertiary details of such 

 a slide. Life would then be filled with pleasures of the 

 sight and mind, unknown to the founders of the diatom 

 culture through the first three-quarters of the Nineteenth 



Century. 

 Mobile;, Alabama, July 5, 1900. 



BIOLOGICAL NOTES. 



L. H. PAMMEL. 



Centrosomes in Plants. — According to Strasburger in 

 his recent work, Histologische Beitrage, the subject of 

 centrosomes is fully discussed. He admits the connec- 

 tion of the spindle fibers with extra nucleoli. Tfjese stand 

 in close relation to the kinoplasm which they are regard- 

 ed as activating. The bodies which different writers have 

 regarded as centrosomes are nothing more than these es- 

 caped nucleoli. In Nymphsea which is said according to 



