1889.] MICE0SC0P1CAL JOURNAL. 35 



Desmids: Their Life History and Their Classification.* 



By Rev. FRED'K B. CARTER, 



MONTCLAIR, N. J. 



Hardly any attention has been bestowed upon the desmids by the 

 microscopists of this country, if we are to judge by the pages of the 

 Microscopical Journal for the past seven years. There are but two 

 or three articles which deal with this subject in all those volumes. Note 

 the multitude of pages on the diatoms and be struck by the contrast. 

 Microscopists seem almost to have gone diatom-mad. The amount that 

 has been written on the l'esolution of fine lines and dots would alone 

 fill a volume. Now, while the attempt to resolve the more difficult 

 diatoms has been vastly beneficial to the makers of objectives, it has 

 not proved of much solid benefit to the amateur. Had he spent a quar- 

 ter of the time he has given to this task in the observation of any one 

 of half a dozen interesting members of the animal or vegetable world, 

 biologically and systematically considered, he would have gotten far 

 more use out of his tube and been able to help others as well. These 

 neglected desmids, for example, are equally worthy of study with the 

 diatoms — far ahead of them in interest if the examination of the latter 

 is confined to the resolution of delicate markings. 



The desmids are to be found everywhere, climate interposing no bar- 

 rier to their distribution, from the north pole to the equator. Wolle 

 says : — ' They are nearly equal in number of species to that of all the 

 other orders of fresh-water algae.' They occur in immense quantities. 

 Last spring a good sized pond in Orange, N. J., was so coated with a 

 single species of Closterium along the border that the mud beneath was 

 almost concealed. The mind wearies as it tries to conceive of the 

 billions upon billions of this single species in that one pond alone. 

 They are of wonderful diversity, ' no other family in the whole range 

 of the plant world presenting such a boundless variety of forms. 'j 

 They are strikingly beautiful in shape and color and markings. 



They are almost at the bottom of the vegetable kingdom, among the 

 lowest of all green things upon the earth, in this respect rivalling the 

 rhizopods in the animal scale. Furthermore, they give us the key 

 to the whole biological problem, the typical cell ; surely here is enough 

 to attract any one. I confess I feel strongly on their neglect. Nor is it 

 strange, since it was a desmid which, by its exquisite symmetry, first 

 really started me on my microscopical work twelve years and more ago. 

 I can see the little beauty as plainly as if it were yesterday. All the 

 surroundings of the room and the persons who were present are pho- 

 tographed on my memory, and I can feel again the thrill of delight that 

 came with the discovery of that Micrasterias. That little plant gave 

 me the first impetus ; created an enthusiasm which has not died out 

 yet, but rather has increased as the years have gone on. No wonder 

 then that the desmids are favorites of mine. 



The desmids are algae which, in the matter of reproduction, resem- 

 ble Palmogloea. Now, Palmogloea is a ' humble Protophyte which 

 presents the phenomena of cell division, conjugation, and gonidial mul- 

 tiplication, under their simplest and most insti'uctive aspect.' A marked 

 feature of all plants is the cells of which they are composed, and as the 



* Read before the Essex County Microscopical Society, Nov. 15, 1888. 

 t Nave's Handy Book of Algse. 



