284 



Scientific Intelligence. 



ing the well-defined casts are of wholly unrecognizable forms, having 

 merely a rounded, cracked, lobed, or even coprolitic appearance. Certainly 

 many of these masses, which oflen compose whole strata, were not formed 

 either in the cavities of Polythalamia or Mollusks. The fact, however, 

 being*established beyond a doubt, that Greensand does form casts in the 

 cavities of various organic bodies, there is a great probability that all the 

 masses of this substance, however irregular, were formed in connection 

 with organic bodies, and that the chemical changes accompanying the 

 decay of the organic matter have been essentially connected with the de- 

 posits in the cavities, of green and red silicates of iron, and of nearly pure 

 silica. It is a curious fact in this connection, that the siliceous organisms, 

 such as the Diatomacea?, Polycistinese, and Spongiolites which accom- 

 pany the Polythalamia in the Gulf Stream, do not appear to have any 

 influence in the formation of casts. 



The discovery of Prof. Ehrenberg, of the connection between organic 

 bodies and the formation of Greensand, is one of very great interest, and 

 is one of the many instances which he has given to prove the extensive 

 agency of the minutest beings in producing geological changes. 



III. BOTANY AND ZOOLOGY. 



1. Wild Potatoes in Neio Mexico and Western Texas. — We have re- 

 ceived from Dr. A. J. Myer, U. S. A., through the Surgeon General, a de- 

 tailed communication on the discovery in western Texas of what he takes 

 to be the common potato (Solatium tuberosum, L.,) in a wild state, ac- 

 companied with specimens of the tubers and of the whole plant neatly 

 dried and prepared. Dr. Myer first detected the plant on and near the 

 Rio Limpio, and afterwards ascertained that it was pretty widely diffused 

 throughout all that region and into New Mexico. The tuber, though small, 

 being rarely as large as a hickory nut, have been gathered, cooked and 

 eaten by officers and soldiers, and they proved to be both palatable and 

 innocent. • It naturally occurred to Dr. Myer that his discovery might be 

 turned to useful account ; that these wild potatoes would probably in- 

 crease in size and improve in flavor under continued cultivation ; and that, 

 if the well-known potato-rot were owing, as many suppose, to an attack 

 of minute Fungi, or to a general debility of constitution resulting from 

 propagation for generation after generation by the tuber, and seldom re- 

 newed from seed, or from both these causes combined, the proper remedy 

 would be to begin anew with a wild stock ; and that these indigenous 

 potatoes of our own country would furnish an excellent stock for the pur- 

 pose, and one which might be expected to resist the disease for a long 

 time, if not altogether. 



Such, in brief, is the substance of Dr. Myer's commendable communi- 

 cation, made to his official superior, the Surgeon General, and by him of- 

 fered for publication in this Journal. The article is too long to be in- 

 serted, however ; especially as the facts and the suggestions it comprises 

 have not the novelty which Dr. Myer naturally supposed they had. But 

 his laudable endeavors and observations ought not to pass unnoticed ; and 

 having given this very brief abstract of his principal points, — which he 



