A Monadine parasitic on Saprolegnieae K 
BY 
MARCUS M. HARTOG, M.A., D.Sc. 
Professor of Natural History , Queen's College , Cork . 
With Plate XXII. B. 
I N my cultures of Saprolegnieae I was for a long time 
perplexed by structures which looked like abnormal spores 
with a gigantic nucleus, and which I at first really regarded as 
such. However, on making cover-glass cultures of 4 cuttings ’ 
(fragments of mycelium removed with a blunt knife) with 
young oogonia, I found to my cost that they were parasitic 
organisms, which demanded careful study. They soon turned 
out to be members of Cienkowski’s group 4 Monadineae,’ now 
regarded as the close allies of Myxomycetes ; and, so far as 
can be judged from the vegetative conditions and zoocysts, 
are referable to the well-named genus Pseudospora Cienk. 2 , 
created in 1865, to receive very similar parasites on the green 
Conjugates and Desmids. The organism is so abundant in 
cultures of Saprolegnieae that it could not escape the notice 
of previous observers. Pringsheim 3 first saw the zoocysts in 
Saprolegnia ( Leptomitus ) lactea y and figured them in company 
with the undestroyed cellulin-corpuscles in an empty hypha. 
He describes them as 4 Eine grosse Anzahl stark mit Inhalt 
erfullter kugeliger Zellen . . . die offenbar keine Schwarm- 
sporen sind. Ihre Bedeutung ist mir noch unbekannt.’ 
Lindstedt in 1872, in his 4 Synopsis Saprolegniacearum,’ 
recognised their true nature. 4 In alteren Faden deren fand 
1 Read at the British Association, Newcastle-on-Tyne, 1889. 
2 Beitrage zur Kenntniss der Monadinen, in Schultze’s Arch. f. Micr. Anat. i. 213. 
3 Jahrbiicher, II. 234, t. xxiii. f. 6. 
[Annals of Botany, Vol. IV. No. XV, August 1890.] 
