Page:Natural History Review (1861).djvu/24

12 are so important and interesting, that we subjoin a portion of them. M. Tulasne says—

"The type of the genus Nyctalis is Agaricus parasiticus of Bulliard, a Fungus which very frequently nourishes in its parenchyma another Fungus, parasitic upon it, viz., Asterophora agaricicola (Cord.), Asterotrichum Ditmari (Bonord.). Its appearance is then so altered, as to have led to its being mistaken by Bulliard himself, who called it by a name different from its former one, viz., Agaricus lycoperdoides. This error has been repeated by Ditmar, and aggravated by Fries, who has imagined that he has found in Agaricus lycoperdoides (Bull ) matter for many different species. More recently, however, Vittadini, Corda, Klotzsch, Berkeley, and other authors, have recognised two different vegetable entities in Agaricus lycoperdoides (Bull.), and we have adopted their opinion. M. De Bary, on the contrary, not only revives Bulliard's view in distinguishing Ag. lycoperdoides (Bull.) from ''Ag. parasiticus (Bull.); but he maintains that the Asterophora (Asterotrichum, Bonord), the presence of which, in our opinion, constitutes the only difference between the first and the second, so far from being a foreign production or vegetable parasite, is nothing less than a secondary reproductive apparatus proper to Ag. lycoperdoides (Bull.) (Nyctalis asterophora'', Fr., Bary). In support of his opinion, he alleges that ''Ag. parasiticus'' (Bull.) alsopossesses an analogous apparatus, and that both in the one and the other Agaric this subsidiary fructification is extremely constant, and always similarly arranged. He admits, however, that the latter excludes the normal or reproductive apparatus, very frequently in ''Ag. lycoperdoides (Bull.), and always, it would seem, in Ag. parasiticus'' (Bull.). He admits also that the secondary spores may well be compared to those of certain fungicolous Fungi, such as Sepedonium, the autonomy and parasitic nature of which he does not venture to doubt. Further, M. De Bary does not deny that it is generally very difficult to make out with certainty, even by the most minute microscopic investigation, the portions of the tissue which belong respectively to the parasite and to its host. This uncertainty, and still more the many reasons to be derived from analogy, weaken the conclusions of M. De Bary. If Asterophora agaricicola (Cord.) so much resembles Sepedonium, may it not, like Sepedonium, be an autonomous parasite, rather than an integral portion of Agaricus lycoperdoides (Bull.); and may not the supposed reproductive apparatus of ''Ag. parasiticus'' (Bull.) constitute another kind of Sepedonium? It has been objected that the organisms in question are always developed in the same place and at the same time, and that they are not met with upon other Agarics; but are not these very characters the distinguishing marks of many admitted Agaricine parasites—for instance, of Sphœria lateritia (Fr ), which is only produced on the hymenium of ''Ag. deliciosus'' (L.), where it causes an almost entire abortion of the gills? Moreover, the supposed secondary fructification of ''Ag. parasiticus'' so nearly resembles on the one hand that of Asterophora, and on the other that of certain Sepedonia, common parasites of the Boleti, as to destroy all our faith in M. De Bary's hypothesis. In our opinion, the proof of the existence of a double fructification in the Agarics must be sought for elsewhere.

"Numerous observations have convinced us that Asterophora, Sepedonium, and Mvcogone are the conidioid condition of species of Sphœria of the genus Hypomyces (Fr.)."

If M. Tulasne' s views are correct, Sepedonium must be struck out of the genera of fungi, as also Trichoderma, which he considers to be only an imperfect state of Hypocrea rufa.

Some few other genera admitted by Mr. Berkeley—for instance, Micropera, Isaria, Helminthosporium, Piggotia, Coniothecium, Aposphœria, and some others, will probably eventually share the same fate; but, in the present state of our knowledge, Mr. Berkeley could hardly