PROGRESS OF MICROSCOPICAL SCIENCE, 133 



The structure of the stems described is identical with that of those 

 found at Autuu by Professor Renault, and assigned by him to Spheno- 

 phljllum ; thus the close affinity of this genus with Aster ojphyllites 

 appears to be finally established. The Calamites verticillatus of authors 

 is probably the arborescent stem of one of these plants. 



The Anatomy of Necrosis. — A paper on this subject was lately read 

 before the Medical Society of Albany (N.Y.), by Dr. W, Hales. The 

 general plan of his remarks was fii'st to treat of necrosis as it occurs 

 in connective tissue, and to compare the processes which natiu-e adoj)ts 

 in dealing with the same affection in the more compact and unyield- 

 ing tissues, as the osseous and tendinous. The subject he illustrated 

 by a series of diagrams of the microscopical appearances of normal 

 and inflamed bone, and a large number of photograjjhic slides made 

 directly from pathological specimens in the museum of the Albany 

 Medical College, thrown upon a white wall by means of the oxy- 

 calcium lantern. The college museum is extremely rich in the variety 

 and number of its specimens, being one of the finest collections in the 

 State. The mode of separation of the sequestrum, the formation of 

 the involucrum, the presence of the living wall of granulation tissue 

 between the septic elements of decaying tissues and the open mouths 

 of absorbent vessels, and the almost complete analogy existing between 

 the various structures in accomplishing the separation of dead parts 

 and the reproduction of the new, were spoken of at length. The 

 microscopic and pathological anatomy of the subject was fully illus- 

 trated. The minute structure of the parts at the different stages of 

 the affection, and the appearance of actual specimens in the various 

 phases of necrosis, were exhibited. The modifications of the vascular 

 supply in different tissues, and their various powers of anastomosis, 

 were fully discussed. 



A Trace of Sexual Organs in the Hymenomycetes. — M. A. CErsted 

 has, says M. Anton de Bary (in a paj)er in ' Grevillea ' for June), 

 discovered a trace of sexual organs in the Hymenomycetes where, 

 perhaps, no one had previously looked for them. He has seen, in 

 fact, in Agaricus variabilis, Pers., oocysts or elongated reniform cells, 

 which sprang up like rudimentary branches of the filaments of the 

 mycelium, and enclose an abimdant protoplasm, if not even a nucleus. 

 At the base of these oocysts appear the presumed antheridia, that is 

 to say, one or two slender filaments which generally turn their ex- 

 tremities towards the oocysts, and which more rarely are applied to 

 them. Then, without ulteriorly undergoing any appreciable modifica- 

 tion, the fertile cell, or oocyst, becomes enveloped in a lacework of 

 filaments of mycelium which proceed from that which bears it, and 

 this tissue forms the rudiments of the cap. The reality of some kind 

 of fecundation in this circumstance, and the mode of the phenomenon, 

 if there is one, are at present equally uncertain. If M. (Ersted's 

 opinion is confirmed, naturally the whole of the cap will be the 

 product of fecundation. As long ago as 1860 M. Karsten presumed 

 that such was the case. His observations on the first development of 

 Agaricus campestris, as far as we can judge by the rather obscure 



