SUBTERRANEAN FUNGI— TUBERACEAE 



195 



classed under the Discomycetes, and may possibly be the same 

 genus with another name. At any rate the Tuber acei are joined 

 to the Discomycetes by these genera, which form the connecting 

 link, and they might almost as well be regarded as aberrant 

 Pezizae as abnormal Tubers. 



One of the largest genera of Tuberaceae, next to the genuine 

 Truffles, is Maphomyces, with its 

 twenty-one species (Fig. 84). The 

 interior mass soon becomes dusty 

 and black, like soot, caused by the 



disappearance of the thin walls of Fig. 83.— Sphaerosoma, with section 



the cavities and the asci which at and spores - 



first enclose the sporidia (Fig. 85), leaving only the free, dark- 

 coloured spores to constitute the internal dust. We collected 



four or five species on one occasion, 

 in a young chestnut wood at 

 Montmore'ncy. All the known 

 species are European, and only 

 one or two of these have been 

 recorded out of Europe. Most of 

 them are nearly globose, and the 

 outer coat is harder than in the Truffles. In former times they 

 had a fanciful reputation in medicine, but have long since gone 

 out of use. 



It will be observed that in the majority of the Tuberaceae, 

 where the pressure is equalised during growth, the asci, which 

 contain the sporidia, approach a globose form, 

 whilst in the genera where the hymenium is effused 

 over the interior, as in those which approach the 

 Discomycetes, the pressure is lateral and the asci 

 assume a cylindrical form, as typical in the fleshy 

 Discomycetes. In none of them are paraphyses 

 present. No facts are known which can lead to 

 the inference that any kind of sexual reproduction is probable 

 in this group ; and although it is believed that the germination 

 of the sporidia results in the production of mycelium, but little 

 is known of the process of germination. Spores, or sporidia, 

 consisting of a single cell appear to be universal, and the 

 form approaches more nearly to the globose than any other. 



Fig. 84. — Maphomyces and section. 



Fig. 85.— 

 Sporidia of 

 Maphomyces. 



