10 REVIEWS. 



as they go, to confirm Pringsheim's account.* We should like also to 

 know the grounds of Mr. Berkeley's opinion, that the mould on flies is 

 only a condition of one of the Saprolegniese. Cohn, Lebert, Braun, and 

 Fresenius, all treat it as an admitted Fungus. f We believe it to be the 

 fact that the bodies of flies, when immersed in water, have not been ob- 

 served to produce the mould, whereas, in such a situation, they fre- 

 quently do produce species of Saprolegnia, but this is hardly sufficient 

 evidence to establish any necessary connexion between the mould and 

 the algae. 



Amongst the diseases caused by Fungi (including, amongst others, 

 dry-rot, the vine mildew, the potato murrain, and many others), ergot 

 holds a prominent place. It affects grains of rye, barley, wheat, and 

 many other grasses, rendering the ears, to use a popular term, "spurred." 

 A good deal has been written, from time to time, on the nature of this 

 disease, and very different opinions entertained ; but there is now hardly 

 any doubt that the so-called " ergotted grains" are, in fact, of the na- 

 ture of a sclerotium, that is to say, that they consist of compact fungoid 

 mycelium. It is not, perhaps, clear whether the individual grains of ergot 

 are purely fungoid, or whether any portion of the albumen of the seed re- 

 mains intermixed with the mycelium. It would seem that Mr. Berkeley 

 inclines to the latter view, for he speaks (p. 73) of the white substance of 

 the seed being converted by the fungus into a firm mass; but we 

 understand Tulasne's opinion to be, J that the seed is entirely displaced 

 by the fungus, and that the grains (so to speak) of ergot are altogether 

 foreign bodies, occupying the place of the seed. M. Tulasne was the 

 first to notice the fact that the grains of ergot give rise eventually to a 

 species of Cordyceps, and that the growth of the Cordyceps may be 

 brought about by sowing the grains of ergot in common garden mould, 

 or keeping them in damp moss. There are still some doubtful points 

 connected with the mode in which the ergot attacks the cereals, and 

 relative to the growth of the Cordyceps from the ergot, which require 

 further observation. Tulasne seems to be of opinion that there is a dif- 

 ference between the ergot which attacks rye, and that which affects 

 other grasses, such as the ergot of the common reed. There is, no doubt, 

 considerable difference in size and appearance between the ergot of rye 

 and the ergot of Phragmites ; and there is as striking a difference be- 

 tween the species of Cordyceps, which is usually produced by ergot of 

 rye, and that which is usually produced by ergot of Phragmites. But 

 then this difficulty arises : — observations subsequent to Tulasne' s§ have 



* " Einige neue Saprolegnieen, Jithrbiicher fur wiss. Bot.," vol. ii., p. 1G9. 



f See Cohn in " Nov. Act. Acad. Nat. Cur." 1855 ; " Fresen. Bot. Zeit.," December 

 1856; Lebert in " Virchow's Arcbiv.," vol. xii., Heft. 1, and in "Neue Denkschrifteu 

 der allg. Schweizerischen Ges. fur die ges. Naturwi.-senchaften," band v., 1857 ; Frese- 

 nius in " Abhandl. der Senckenbergischer Nat. Gesellschaft," band xii., 1858, p. 201 ; 

 "Braun AlgSB unicellulares, Lips." 1855, p. 105. 



+ "Ann. des Sc. Nat," 3rd Ser., vol. xx., p. 11. 



§ See "Bot. Zeitung," Feb. 2, 1855, and "Quart. Journ. of Microscopical Science," 

 vol. v , p. 133. 



