CHAPTER V.—COMPARATIVE REVIEW.—MUCORINT. 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. Nachträge z. Morphol. d. Saprolegnieen 
(Jahrb. f. wiss. Bot. II, 1860, p. 205) ;—Id. Weitere Nachträge, &c. (Jahrb. f. wiss. 
Bot. IX, 1874, p. 191). 
DE Bary, Einige neue Saprolegnieen (Jahrb. f. wiss. Bot. II, p. 169) ;—Id. Beitr. 2. 
Morphol. und Physiol. d. Pilze, IV (1881). 
HILDEBRAND, Mycolog. Beitr. I (Jahrb. f. wiss. Bot. VI, 1867, p. 249). 
LEITGEB, Neue Saprolegnieen (Jahrb. f. wiss. Bot. VII, 1869, p. 357). 
K. LINDSTEDT, Synopsis d. Saprolegniaceen (Diss. Berlin, 1872). 
M. CORNU, Monographie der Saprolegniées (Ann. d. sc. nat. ser. 5, XV); see page 139 
above. 
P. REINSCH, Beob. ü. einige neue Saprol. (Jahrb. f. wiss. Bot. XI, 1878, p. 283). 
M. BÜSGEN, 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 1881 cited above. 
MUCORINI. 
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] L 
