less rich in spores. They are, in short, less fat and flourishing 

 than Mr. Eaton's prosperous plants from New England. It is the 

 same sort of difference as that found in /. saccharata from 

 Wicomico river and the same species from the head of Chesapeake 

 bay. No doubt such variation is to be charged to environment * 

 Dr. Best has kindly answered numerous questions as to 

 plants and habitat. He first collected the species at Point Pleas- 

 ant about ten years ago, and has not seen it elsewhere. He has 

 frequently pointed it out to visiting botanists. The locality is far 

 above tide, and is a broad, gently sloping river-bed, "made up 

 chiefly of cobblestones and coarse sand or gravel." This bed is 

 lightly covered with mud, and is "wet, but not submerged except 

 in time of flood." The Isoetes has almost no other plants for 

 company, and is exposed to the full glare of the sun. It often 

 grows in the edge of the water, but sometimes farther back 

 toward the bank, for even here every now and again it will be 

 submerged for a little while at a time. It will be noticed that 

 this habitat resembles in a manner the East Kingston mud flat, 

 where Mr. Eaton first gathered and recognized the species, and 

 that it is altogether unlike the tidal banks beloved of /. riparia 

 and /. saccharata. 



MICROSPORES. 



The microspores, alike in Mr. Eaton's plants and in those of 

 Dr. Best, are distinctive. The former gentleman has (Fern 

 Bulletin 6 : 6) described them, and has pointed out their great 

 variation in size. Students of this genus will have a mental pict- 

 ure of the ordinary Isoetes microspore. It is, as a rule, in the 

 form of a gentle crescent with very shortly frustrate and rounded 

 ends, and with a central inflation on the concave side. Now this 

 is the shape of possibly the majority of those of /. Dodgei. But 

 intermingled with these, even in the same sporangium, are 

 numerous larger ones, nearly or quite spherical, and sometimes 

 twice the usual size. Their significance, and their development 

 into cells containing spermatozoids, would be no bad subject for 

 investigation. As to their origin, Mr. Eaton, in a recent letter, 

 states his view to the effect that they are an overgrowth of " one 

 of the four spores normally present in each mother cell, the other 



* " When growing gregariously the leaves of /. Dodgei are more drawn 

 out and straight, the trunks always small. Well developed plants with 

 characteristic twisted leaves are only found where there is plenty of room, 

 when even the submerged leaves are tortuous." — Eaton. 



