On the Development of the Root-cell and its Nucleus in Chara. 13 



were I disposed to admit into it those forms which I have de- 

 tected, after a careful examination, sparingly distributed through- 

 out the material when finally prepared for mounting. But I am 

 reluctant to put forward as new species, or even as well-esta- 

 blished varieties, forms whose characters rest upon what my 

 knowledge of these organisms obliges me to regard as insuffi- 

 cient and unsatisfactory evidence. Not to dwell upon the liability 

 to accidental intermixture to which such materials are liable, 

 which, as every practical microscopist is aware, defy his most 

 careful attention, and frequently intrude upon a gathering fx'om 

 one locality stray frustules belonging to a very different habitat, 

 I consider it impossible to decide upon the specific claims of any 

 but the most conspicuously marked Diatomaceous forms, from 

 an examination of a few isolated specimens. In such genera as 

 Cymbella, Navicula, Pinnularia, Cocconema, and others, where 

 there exists great simplicity of outline combined with great 

 diversity of size, a knowledge of the form under examination, 

 from difierent localities and at different periods of development, 

 is absolutely necessary to enable the observer to determine its 

 specific character, and to warrant him in referring it to a known, 

 or erecting it into a new, species. Better to leave its claims sub 

 lite until more satisfactory evidence is afforded, than to introduce 

 confusion into the nomenclature of the science, and uncertainty 

 into our conclusions with regard to geographical distribution, by 

 a hasty, insufficient, and temporary determination. The an- 

 nouncement of a new species is sometimes nothing more than 

 the publication of the observer's imperfect knowledge : the for- 

 bearance which foregoes the eclat of a " discovery," is often a 

 homage due to the inexhaustible resources and the infinite 

 vaiiety of nature. 



II. — On the Development of the Root-cell and its Nucleus in 

 Chara verticillata {Roxb.). By H. J. Carter, Esq., Assistant 

 Surgeon H.C.S., Bombay. 



[With a Plate.] 



Last year I found it necessary, on account of the investigations 

 I was then making, to ascertain the physical features which the 

 protoplasm of the first few cells of Chara presented on their 

 development from the nucule ; but, not requiring to go further, I 

 merely commenced from the bursting of the vacuoles of the new 

 protoplasm into each other, and followed this up to the full de- 

 velopment of the rotatory motion*. Latterly I have found it 



* Ann. and Mag. Nat. Hist. vol. xvii. pp. 110 & 111. pi. 8. fig. 35, 1856. 



