152 THE MICROSCOPE. Oct. 



One of the Questions that Meets the Student of Bacil- 



laraceae. 



BY ARTHUR M. EDWARDS, M. D. 



NEWARK. N. J. 



The finding of "species," as they were called by the 

 older observers, and the naming of them is not the duty 

 of the true student of the Bacillaracese. The naming of 

 them is easy enough; if a name cannot be found that 

 suits their peculiarity, a name of some person or place 

 can be substituted. But when we come to give a name 

 which describes their peculiarities is is more diflBcult. 

 For instance, it is easy to name a little boat-shaped 

 green cell when it is recent and call it Navicula viridis. 

 But when the boat-shaped cell is twice or three times as 

 large it may be called Navicula, or little boat, which is 

 larger, or major. But this is giving a "specific" name 

 to the object and it has not a right to the "specific'' 

 name. For it is a sporangium, as it is called, of Navi- 

 cula viridis. So with other so-called species. The find- 

 ing out the why and wherefore of things and of their 

 being is the true duty of every naturalist. 



Some time ago the question of whether the Diatom- 

 acsB or Bacillaracese were single or multiple cells 

 came up in the investigations of Dr. Wallich, and he 

 contributed a paper to Popular Science Review on the 

 subject. I do not remember what conclusion he came to, 

 but this is what I came to — the BacillaracesB or Diatom- 

 acse are multiple cells. Again I am puzzled to meet the 

 question, for there are certain peculiarities that appear 

 as the magnification, if the Bacillaracese is made more 

 clear by modern objectives. Again, I am inclined to the 

 multiple side of the question. And for this reason, 

 Pediastrium granulatum, F. T. K., an extremely common 

 Desmid, was examined in Peckman's Brook, N. J., this 

 May. This is a beautiful form, being like a green star. 



