HYPHOMYCETES.

With regard to the Hyphomycetes, Cooke takes the ground that in their internal relations to each other, and their external relations to the remaining orders, the Hyphomycetes are undoubtedly a well-defined and natural group, and should have place as such in a systematic work. It is a large order, containing nearly 5,000 species, mostly parasitic on dead animals and vegetable matter. The spores, termed conidia, are free, as in Hymenomycetes. The species are microscopic in size, and the hyphæ are strongly developed. They have no hymenium and no true basidia, and are non-sexual in their reproduction.

The four primary sections are the Mucedineæ, or "white moulds;" the Dematieæ, or "black moulds;" the Stilbea, with the hyphæ or thread-like filaments pallid or brown, and densely cohering, and the Tubercularieæ, with the hyphæ densely compacted in wart-like pustules of somewhat gelatinous consistency.

The divisions called Melanconieæ, Sphæropsideæ, and Hyphomyceteæ are not recognized in the Brefield system of classification as distinct groups. Massee and Cooke, with other mycologists, take exception to this omission and its implication, in their discussion of the subject, giving consistent reasons for the retention of these groups in systematic works.