CHAPTER V. COMPARATIVE REVIEW. PROTOMYCES. 171 



Literature of the Chytridieae : 

 A. BRAUN, Ueber Chytridium, eine Gattung einzelliger Schmarotzergewachse (Monats- 



ber. d. Berlin. Acad. Juni, 1855, and Abhandl. derselb. Acad. 1855, p. 21, tt. 1-5); 



Id., Ueber einige neue Arten v. Chytridium u. d. damit verwandte Gattung Rhizidium 



(Monatsber. d. Berlin. Acad. i Dec. 1856). 



F. COHN, Ueber Chytridium (Nov. Act. Leop. Car. 24, I, p. 142). 

 BAIL, Chytridium Euglenae, Ch. Hydrodictyi (Bot. Ztg. 1855, p. 678). 

 CIENKOWSKI, Rhizidium Confervae glomeratae (Bot. Ztg. 1857, p. 233). 

 A. SCHENK, Algol. Mitth. (Verhandl. d. Phys. Med. Ges. z. Wiirzburg, Bd. VIII); 



Id., Ueber d. Vorkommen contractiler Zellen im Pflanzenreiche, Wiirzburg, 1858 



{Rhizophydium). 

 DE BARY u. WORONIN, Beitr. z. Kenntn. d. Chytridieen in Ber. d. naturf. Ges. zu 



Freiburg, III (1863) and Ann. d. sc. nat. se'r. 5, III (Synchytrium). 

 DE BARY, Beitr. z. Morph. u. Phys. d. Pilze, I, in Abhandl. d. Senkenb. Ges. Frank- 

 furt, 1864 (Cladochyrrium Menyanthis). 

 WORONIN, Entwicklungsgesch. v. Synchytrium Mercurialis (Bot. Ztg. 1868, p. 81) ; Id., 



Chytridium Brassicae (Pringsheim's Jahrb. Bd. XI, 1878, p. 557). 

 KNY, Entwicklung v. Chytridium Olla (Sitzungsber. d. Berliner Naturf. Freunde). 



See also Bot. Ztg. 1871, p. 870. 

 M. CORNU, Chytridine'es parasites des Saprolegnides in Ann. d. sc. nat. se'r. 5, XV 



(1872), p. 112 (Olpidiopsis, Rozella, Woronina, &c.). 

 J. SCHROTER, Die Pflanzenparasiten aus d. Gattung Synchytrium (Cohn's Beitr. z. 



Biol. I, i, 1875) ; Id., Ueber Physoderma (Berichte d. Schlesischen Ges. 1882). 

 L. NOWAKOWSKI, Beitr. z. Kenntn. d. Chytridiaceen in Cohn's Beitr. z. Biol. II (1876), 



p. 73 (Chytridium, Obelidium, Rhizidium, Cladochytrium) ; Id., Polyphagus 



Euglenae (Cohn's Beitr. z. Biol. II, p. 201) ; Id., Ueber Polyphagus, in Polish (Abh. 



d. Krakauer Acad. 1878). 

 A. FISCHER, Ueber d. Stachelkugeln in Saprolegniaschlauchen (Olpidiopsis) in Bot. 



Ztg. 1880) ; Id.. Unters. ii. d. Parasiten d. Saprolegnieen (Habilitationsschrift, 



Berlin, 1882, and Pringsheim's Jahrb. Bd. XIV). 



PROTOMYCES AND THE USTILAGENEAE. 



SECTION LIII. Protomyces macrosporus (Fig. 79) is a parasite which lives 

 in the intercellular spaces of umbelliferous plants, especially Aegopodium; it has a 

 branching filiform mycelium with transverse segmentation, which produces numerous 

 intercalary resting-spores and then dies. The resting-spores, which may be more 

 than 60 p in diameter, are irregularly ellipsoid in shape, filled with dense fatty proto- 

 plasm and provided with a very thick many-layered cellulose-membrane. They 

 germinate after hibernation in water when set free by the decay of the umbellifer. In 

 germination the endosporium with the protoplasm which has become finely granular 

 swells into a spherical vesicle, bursts the thick layers of the episporium, and issuing from 

 it becomes a sporangium. A large number of rod-like spores only about 2.2 p in length 

 are formed in a sporangium in the manner described in section XIX and are ejected 

 from it; they are thin-walled and without independent movement, but show slight 

 oscillations caused by currents in the water ; they are thus brought into close proximity 

 with one another if this has not happened directly by ejection, and conjugate in pairs 

 by means of slender processes usually in the form of the letter H. Scarcely anything 



