Brooks.] 236 [February 16, 



pods, however, and thus introduces a difficulty at least as great as 

 that which it removes. At present the safest plan seems to be that 

 of waiting for more knowledge, bearing in mind the existence of this 

 at present insoluble difficulty. 



Mr. S. H. Scudder gave an account of the mode in which 

 the hind wings of Orthoptera, and especially of Cockroaches 

 and Earwigs, are folded in repose, showing the gradual steps 

 from a simple to a very complex duplicature, which these 

 insects present. 



Mr. Bouve exhibited three specimens of rock, lately ob- 

 tained from a ledge at Hyde Park within eight feet of each 

 other, and pointed out the gradation from true conglomerate 

 to true porphyritic structure, which they exhibited. 



Dr. W. K. Brooks exhibited a cast of a viviparous fish 

 (Embiotica) from California, showing the young in situ, and 

 also a cast of the monstrous form of the human uterus, 

 known as " Uterus bicornis? Both casts were the work of 

 Dr. Nardyz of Cleveland, in whose name Dr. Brooks pre- 

 sented them to the Society's Museum. The thanks of the 

 Society were voted for these gifts, and also to Messrs. Brooks 

 & Torrey, of Boston, for grinding a number of porphyries 

 for the collection. 



February 16, 1876. 



The President, Mr. T. T. Bouve, in the chair. Forty- 

 three persons present. 



Dr. W. G. Farlow made some remarks on the nature and 

 mode of growth of the black knot which attacks plum and 

 cherry trees. 



The knot is not of insect origin, as some have supposed, but is due 

 to a fungus described by Schweinitz under the name of Sphceria mor- 



