792 SUMMARY OF CURRENT RESEARCHES RELATING TO 



to obtain, at various stages, it is seen that at a certain period the ascogone 

 breaks up into a mass of cells. The wall of the perithecium becomes now 

 differentiated into an outer brown layer and an inner layer, the cells of 

 wLich continue to increase in size, and rhizoids are formed from the lower 

 portion, distinguished by their brown colour and irregular curving. A 

 cavity is now formed in the central group of cells, bounded by the cells 

 formed out of the ascogone, the upper layers of which disappear, while the 

 lower layers remain. The cells of the walls of the perithecium which 

 bound the cavity elongate into tubes which are periphyses, and those which 

 still remain of the ascogone-cells also elongate vertically into filaments, 

 which constitute a cushion, and from the rods which form this cushion are 

 developed the asci. There are no paraphyses. As the asci are developing, 

 an opening is formed to the perithecium, before the ascospores are fully de- 

 veloped. The mode in which the ascospores escape from the asci is not cer- 

 tain, but the perithecium becomes gradually filled with them, fresh asci being 

 constantly formed. The author regards the " nucleophyses " of Zopf as 

 simply periphyses. 



The life-history was also followed out of C. hostrychodes, murorum, 

 pannosum, and crispatum, differing only in unimportant points from that 

 of G. Kunzeanum. 



Gonidia are freely formed in cultures which have exhausted their nutrient 

 solution. They have no connection with the perithecia. 



As regards its systematic position, the author considers Ghsetomium as 

 most nearly allied to Melanospora. 



MycorMza.* — M. H. Lecomte states that he has found mycorhiza on 

 the roots of various trees, particularly the beech, chestnut, oak, and hazel. 

 On the roots of the hazel conidia and two perithecia have been observed. 

 The first perithecium, found in September, was only 35 /x, in diameter ; the 

 second, observed in November, was nearly spherical, and had a diameter of 

 46 fju. The perithecium was composed of pseudo-parenchyma. "When 

 pressed five brownish spores escaped. The spores were each formed of a 

 thread of four cells, and resembled certain spores of Perisporium. Their 

 length was 12 [x. The conidia were borne by colourless filaments ; some 

 were terminal, and some inserted laterally on the filaments. The conidia 

 were elongated, and composed of two cells. Their length was about 14 /x.. 



The author states that it is not possible to actually determine the true 

 affinities of this fungus, although in a great many of its characters it 

 approaches the Perisporiace^. 



"New pathogenous species of Mueor.f — In addition to the only two patho- 

 genous species of Mucor hitherto known, M, rhizopodiformis and corymbifer, 

 Herr W. Liudt now describes two others, M. pusillus and ramosus. The 

 former is distinguished by its very small size, the sporangiophore rarely 

 exceeding 1 mm. in length. M. ramosus resembles M. corymbifer, but has 

 larger spores. The infection-experiments were made on rabbits ; a Mucor- 

 mycosis resulting, altogether different from an Aspergillus-mjcoBiB, and 

 presenting the same pathological characters as that of the two species 

 already known. 



Fungous Diseases of Plants.^— Mr. W. B. Grove finds that the EucJiaris 

 disease is due to the attacks of Saccharomyces glutinis, which attacks also 



* Bull. Soc. Bot. France, xxxiv. (1887) pp. 38-9. Cf. this Journal, 1886, p. 113. 

 t Lindt, W., MT. iib. einige neue pathogene Schimmelpilze (1 pi.)) Leipzig, 

 1886. See Bot. Ztg., xlv. (1887) p. 204. 



X Rep. Brit. Assoc. Birmingbam Meeting, 18S6, p. 700. 



