Proceedings of the- 



not be right in his conjecture as to the fitness of some of the French 

 trees for that purpose, they would necessarily perish. In conclusion, 

 the reporter, though bestowing great praise on M. Lamare Picquot's 

 assiduous labour, appears rather to discourage the introduction of the 

 Bombyx paphia, on the ground, first, of the uncertainty of being 

 able to nourish it ; and secondly, that if the silk be useful, it would 

 probably be as economical to get it in a raw state from India. 



At the conclusion of this report, M. Chevreuil stated that he had 

 been engaged in endeavouring to bleach the silk in question, but had 

 not yet been able to succeed in doing so ; although he had consi- 

 derably diminished the intensity of the dark colour. He added, that it 

 is undoubtedly chemically different from common silk, and would 

 require to be carefully analysed before it was adopted as an article of 

 commerce, since the chemical tests now used at the Custom-house to 

 ascertain the purity of common silk would not produce the same 

 effect on this. M. Chevreuil concluded by expressing an opinion 

 that this silk is not a simple substance, but a combination of several. 



Apoplexy in Horses. On the 15th of August, M. Bouloy pre- 

 sented a memoir to the Academy, from which it appeared that apo- 

 plexy of the spinal marrow is as frequent in horses as apoplexy of 

 the brain is in men ; an observation in perfect and curious accord- 

 ance with the relative degree of activity of those two organs in the 

 two species of animals. 



Teeth of the Gnawing Mammifertz. On the llth of July, M. 

 Geoffrey St. Hilaire read a memoir, the object of which was to prove 

 that the front teeth of these mammiferee, which have been hitherto 

 called incisors, are, in fact, analogous to the canine teeth. For 

 this purpose he entered into the history of the names given to the 

 teeth in different animals. In the human anatomy, teeth were 

 divided into three classes the incisors, the canine, and the molares or 

 grinders ; and the same names were without difficulty applied to the 

 families whose organization most resembled that of man, such as the 

 quadrumani and the carnivorous. After these families, however, 

 came animals which are digitated, but have but two sorts of teeth, 

 and this circumstance became the characteristic of one of the great 

 orders of mammiferae, that of the rongeurs. There was not much 

 time spent in inquiring in which class of teeth these animals were 

 deficient. Teeth were observed placed in the front part of the jaw, as 

 incisors are in man. The front teeth of the rongeurs were, therefore, 

 immediately called incisors, which name some zoologists afterwards 

 changed to primores, a term which had the double advantage of 

 expressing that these teeth are the first which offer themselves to 

 observation, and that they present a characteristic of the first order 

 of zoological importance, inasmuch as their variation is always con- 

 nected with a great number of others in the organization. The name 

 of incisors was, therefore, given to these front teeth, merely because 



