148 Egg Parasites and their Relatives. 



legnia was first established by Nees von Esenbeck, lias been 

 now extended with certain modifications to the whole group ; 

 and on this account, in addition to their aquatic habits, these 

 plants have been associated with the Algas, though then 

 appearance and habit are rather those of some of the moulds. 

 Carus, however, in investigating a mouldy appearance which 

 arose on a dead salamander, having immersed half in water 

 and kept the other half moist in air, obtained from the latter 

 an undoubted species of Mucor, while from the former he 

 obtained Achlya prolifera, Nees (Figs. 10 — 12). This was 

 taken at the time as a strong argument for the instability of 

 the lower plants, while in truth it was only one amongst many 

 proofs of a fact which was then unknown, but has since been 

 amply manifested, that in these lower plants there is a duality 

 or plurality of modes of fructification. Indeed, though the 

 active spores, moving- about with one or more lash-like appen- N 

 dages, resemble exactly the reproductive bodies which are so 

 common amongst AlgEe, there is now evidence amongst moulds, 

 as in the genera Peronospora and Cystopus, and still more 

 amongst the Myxogastres, that there are active spores amongst 

 true Fungi. The difficulty, therefore, in great measure, ceases, 

 and I have not a doubt left in my own mind about the subject, 

 while I consider my remarks in the introduction to Cryptogamic 

 Botany, which have been called in question, fully confirmed. 



Correct information as to the structure of these curious 

 parasites has been obtained but slowly, and as it is scattered 

 up and down amongst a variety of journals, it is proposed to 

 give here a sort of precis, without any pretensions to novelty. 

 The most complete account is that by Pringsheim, in his Journal 

 of Scientific Botany.* His definition of three of the genera to 

 which these animal parasites arc referrible is here given nearly 

 in his own terms, to which is added a fourth, Aphanomyccs, pro- 

 posed by Do Bary. 



K'l/ifohynia, Nces v. Escnb. — Infusorioid spores formed in 

 the interior of the sporangia, and immediately alter their forma- 

 tion isolated and active without any previous membrane. New 

 sporangia formed by the repeated protrusion of the basal mem- 

 brane into the old sporangium. Oogonia containing numerous 

 resting spores. (Figs. 1 — 8.) 



Achlya, Nees v. Esenb. — Infusorioid spores formed in the 

 interior of Hie sporangia, but after their formation collected in 

 ahead at the point of issue, and olothed with a membrane. 

 The basal membrane of the sporangia forming Lateral sporangia 

 by protrusion at the base of the primary sporangia. Besting 

 spores numerous in bhe Oogonia. (Figs. 10 — 14.) 



* Jahrtraober (ur WiMeDshaftliche Botanik lierausgcgcben von I)r. N. Prings- 

 heim, ]8G7 and 1589. 



