NOTES AND OBSERVATIONS ON BOARD H.M.S. RATTLESNAKE 



What animals are there then which consist either of simple cells or 

 of cells aggregated together, which hold the same rank among animals 

 that the Diatomaceai and Desmidise, the Protococci and Palmella; hold 

 among plants ? 



Ten years ago the general reply of zoologists would have been— 

 none. The researches of the celebrated Berlin microscopist, Prof 

 Ehrenberg (wonderful monuments of intense and unremitting labour, 

 but at least as wonderful illustrations of what zoological and physio- 

 logical reasoning should not be), led to the belief that the minutest 

 monads had an organization as complicated as that of a worm or a 

 snail. In spite, however, of the great weight of Prof Ehrenberg's 

 authority, dissentient whispers very early made themselves heard, from 

 Dujardin, Focke, Meyen, Rymer Jones, and Siebold. To these Kol- 

 liker, Stein and others — in fact, I think I may say all the later 

 observers — have added themselves, until it really becomes a matter of 

 duty on the part of those interested in the progress of zoology to pro- 

 nounce decidedly against the statements contained in the ' Infusions- 

 thierchen,' so far as regards anatomical or physiological facts.i 



It has been shown in the first place, that a great mass of the so- 

 called Polygastria are plants — at any rate are more nearly allied to 

 the vegetable than to the animal kingdom. Such is the case with the 

 DiatomaceEe and Desmidife, the Volvocina, the Monadina, the 

 Vibriones, and to these we must very probably add the Astasia;a. 



So utter has been the want of critical discrimination in the con- 

 struction of genera and species, that Cohn, in his admirable memoir 

 upon Protococcus pluvialis, enumerates among the twenty-one forms 

 (to which distinct names have been given by authors) assumed by the 

 Protococcus, no less than eight of Prof Ehrenberg's genera. The family 

 " Polygastria," thus cut down to less than one-half its original dimen- 

 sions, contains none but animals which are either simple nucleated 

 cells, or such cells as have undergone a certain amount of change, not 

 sufficient however to destroy their real homology with nucleated cells. 



A nucleus has been found in Eugleiia, Arcella, Amosba, Aviphileptus, 

 Trachelius, Bursaria, Paraumciuvi, Nassula, Chilodon, Oxytricha, 

 Stylonichia, Stentor, Vorticella, Eiiplotes, Trkhoduia, Loxodes, and 

 other genera. It may be brought out by acetic acid just like any 

 other nucleus in Vorticella and Euglena. 



1 That the above assertions will be considered by the majority of English readers to be 

 unwarrantably severe, and considering the relative standing of the Professor and his critic, 

 possibly impertinent, is no more than is to be expected. 



I can only beg to disclaim all mere iconoclastic tendencies, and refer to a comparison of 

 Prof. Ehrenberg's works with facts for my justification. 



