and offering the appearance as if there was a semi-transparent mass attached to the larger end. The size was estimated at from a fifteenth to the twenty-thousandth of an inch. After a careful examination I was unable to detect any vegetable or organic nucleus which might have served as a nidus for these masses of infusoria. They would seem to become developed in the pure sand, or at least in the sand as it was blown up from the beach, after the salt had been washed out of it by the rain. [I would remark that it had been raining some days before I collected them.] Subsequent researches have shown that these infusoria are very generally diffused through the sands that form our drifting sand-hills around the city; and on examining some sand taken at a depth of fourteen feet from the surface, where the hills were being cut through, I found it full of well developed infusoria on placing it under the microscope a few minutes after it had been collected, so that there can be no doubt but that these infusoria were present in the sand at the time it was collected, where they had probably been in a torpid state for ages. It is possible that they might have been carried there by the infiltrating water during the rains; but I am inclined to think that they had been torpid there, as the circumstances in which they were placed were not favorable for propagation except by fission, a process that cannot be carried on indefinitely, even in these lower organisms. In fact, these infusoria, taken from the deep sands, copulated most extensively the moment they were placed in water. I am not aware that analogous observations have been made as to the office of these lower infusoria in fixing the moving sands, and thus initiating that series of changes by which they eventually become clothed with verdure; the first germs of organic life being generally supposed to be established by the lower vegetable organisms. Dr. Kellogg presented the following paper: Description of Two New Species of Plants. BY A. KELLOGG, M.D. CONYZA Less. _C. salicena_ Kellogg. [FIG. 6.] [Illustration: FIG. 6.]