CHAPTER V. — COMPARATIVE REVIEW. — MUCORINI. 145 



and Phytophthora. All beside remains untouched ; especially the absence of sexuality 

 in the species, forms, and individuals, which have no antheridia producing fertilisation- 

 tubes. 



For the details of these disputed points the reader is referred to the publications, 

 which are cited at the close of the following list and which have appeared since the 

 year 1882. 



Literature of the Saprolegnieae. 



N. Pringsheim, Entwicklungsgeschichte d. Achlya prolifera (N. Acta Acad. Leo- 



poldin. Carolin. 23, I, pp. 397-400). 

 A. DE Bary, Beitr. z. Kenntn. d. Achlya prolifera (Bot. Ztg. 1852, p. 473). 



Both these works contain also a record of the earlier copious literature of the subject. 

 Pringsheim, Beitr. z. Morph. u. Systematik d. Algen, II ;— Id Die Saprolegnieen in 



Jahrb. f. wiss. Bot. I, 1857, p. 284 ; — Id. Nachtrage z. Morphol. d. Saprolegnieen 



(Jahrb. f. wiss. Bot. II, i860, p. 205) ; — Id. Weitere Nachtrage, &c. (Jahrb. f. wiss. 



Bot. IX, 1874, p. 191). 

 De Bary, Einige neue Saprolegnieen (Jahrb. f. wiss. Bot. II, p. 169) ; — Id. Beitr. z. 



Morphol. und Physiol, d. Pilze, IV (1881). 

 HlLDEBRAND, Mycolog. Beitr. I (Jahrb. f. wiss. Bot. VI, 1867, P- 2 49)- 

 Leitgeb, Neue Saprolegnieen (Jahrb. f. wiss. Bot. VII, 1869, p. 357). 

 K. Lindstedt, Synopsis d. Saprolegniaceen (Diss. Berlin, 1872). 

 M. Cornu, Monographie der Saprolegniees (Ann. d. sc. nat. ser. 5, XV) ; see page 139 



above. 

 P. Reinsch, Beob. ii. einige neue Saprol. (Jahrb. f. wiss. Bot. XI, 1878, p. 283). 

 M. BUSGEN, Entwickelung d. Phycomycetensporangium in Diss, and Pringsheim's 



Jahrb. XIII, Heft 2, 1882. 



N. Pringsheim, Neue Beobacht. ii. d. Befruchtungsact v. Achlya u. Saprolegnia 



(Sitzungsber. d. Berlin. Acad. 8 Juni, 1882) ; — Id. in Jahrb. f. wiss. Bot. XIV, 



Heft 1. 

 De Bary in Bot. Ztg. 1883, Nr. 3. 

 See also Zopf and Pringsheim in Bot. Centralblatt, 1882, Nr. 49, 1883, Nr. 25 and 31. 



Some smaller treatises have been already noticed in the text and in my publication 



of 1 88 1 cited above. 



MTJCOEXNT. 



Section XLI. The Mucorini or Zygomycetes agree very nearly both in 

 structure and in the course of their development with the Peronosporeae and 

 Saprolegnieae, but there is this essential difference between them, that, instead of the 

 oospores which have just been described in the two latter groups, the Mucorini form 

 zygospores, which are typically produced by the coalescence, conjugation, of two nearly 

 or perfectly similar cells of separate origin (gametes). The formation of zygospores 

 is not the only form of propagation in any known species of the group. On the 

 contrary they all produce gonidia as well, and the gonidia in some species have 

 considerable variety of form owing to complicated life-conditions and adaptations, 

 and in all are much more abundant than the zygospores. Even in species where the 

 zygospores are comparatively abundant the gonidia predominate to such an extent, 

 that they propagate the species unaided through many successive generations, 

 the zygospores on the whole rarely arriving at their full development. In some 

 species the zygospores are great rarities ; in a whole series of forms, which it cannot 

 be doubted are in other respects closely related to the species which produce 

 [4] 



