30 PATRICK GEDDES. 



Observations on the Resting State of Chlamydomyxa laby- 

 RiNTHULOiDEs, Aicher. By Patrick Geddes^ E.E.S.E., 

 Lecturer on Zoology iu the School of Medicine, Edinburgh, 

 and Demonstrator of Botany in the University. (With 

 Plate V.) 



I RECENTLY received from Professor Dickson a plant of 

 8])hagnimi, forwarded by Professor Perceval Wright, from West- 

 meath, and laden with specimens of Cidamydomyxa lahpinthu- 

 loides, Archer, a remarkable organism upon which nothing 

 further has been written since the paper by its discoverer, which 

 appeared in this Journal in 1S75,' I have not had the good 

 fortune to witness the remarkable motile labyrinthuloid state, so 

 fully described and beautifully figured by Mr. Archer; this, 

 however, is not to be wondered at, since he mentions that even 

 in the natural conditions, its occurrence is occasional and 

 capricious. My attention has therefore been confined to the 

 resting state, on which I have been able to confirm, and have 

 attempted somewhat to extend, his observations. 



From such average adult resting forms as those figured by 

 Mr. Archer, or again at PI. V, fig. 13, of the present paper, 

 there are to be found absolutely perfect gradations to such forms 

 as those represented at figs. 1 a and 2. These are spherical, 

 with their cellular walls filled with protoplasm uniformly coloured 

 with chlorophyll, save usually for one bright red speck. They 

 are usually alone, but are occasionally grouped, generally in 

 twos or fours. Their resemblance to Proiococcus phwialis is 

 extremely striking, in fact it would be easy to place specimens 

 under the microscope which would be necessarily so termed by 

 every observer unacquainted with Chlamydomyxa. It is only by 

 their extreme variability, by the existence of every possible 

 gradation from these forms downwards to others much smaller 

 than ordinary Protococci, and upwards to the massive and irre- 

 gular bulk of a full-grown Chlamydomyxa (which is quite visible 

 to the naked eye), that one is enabled to recognise that these 

 are simply young specimens of the latter in what we may hence- 

 forth term the Proiococcus stage. 



As growth goes on, the little mass, usually enclosed within a 

 cell of the Sphagnum leaf, remains spherical until it touches its 

 prison wall, when — one diameter being henceforth retained — it 

 proceeds to grow lengthwise, proceeding often for a considerable 



1 'Quart. Journ. Mic. Sci.,' vol. XV, 1875, P). VI, "On a New 

 Sarcodic Organism," &c. 



