
WHAT IS A DESMID? 
BY PROF. ARTHUR MEAD EDWARDS. 

In the language of science, as put upon paper by one of 
its most zealous deyotees, Desmids, or as they are more 
correctly designated, Desmidiacez, are “fresh-water, figured, 
mucous and microscopic alee, of a green color." This 
author also tells us in similar language that the character- 
isties of these fresh-water forms are “transverse division 
mostly complete, but in some genera incomplete. Cells or 
joints of two symmetrical valves, the junction always marked 
by the division of the endochrome, often also by a constric- 
tion. Sporangia formed by the coupling of the. cells and 
union of their contents.” 
We have here then, in brief, what a Desmid is, and now 
let us see if we can make this very concise, scientific and 
‘ correct definition and reply to our question, plain to unsci- 
entific minds. 
The difficulties attendant upon the study of these Desmids 
have perhaps, tended to frighten away even professed natu- 
ralists from a field of enquiry teeming with promise of re- 
sults of the greatest interest and profit. At least then we 
have arrived at the knowledge of one fact, and that is, that 
à Desmid is a plant, or a member of the vegetable kingdom. 
This point, it is true, is all but universally acknowledged by 
every one who pretends, to any acquaintance whatever with 
these creations, and therefore for the time being we will 
take it for granted that such is the case. In fact it is true 
that there is no one essential point in which they differ from 
the other minute plants which have been included under the 
designation of Protophytes ; this name having been applied 
to them on account of the simplicity of their structure, 
‘Tanking them as first plants in the vegetable system. Bob 
Although the name Protophyte was first bestowed for this 
AMER. NATURALIST, VOL. III. 40 (313) 
















