

1855.] PASSING VISITS TO THE RICE LAKE, RIVER HUMBER, GRENADIER'S POND, &c. 



201 



TORONTO, APRIL, 1855. 



Passing Visits to the Rice Lake, Humber River, Grenadier's 

 Pond, and the Island. 



Made by Dr. Goadby and J. ISoveli., M.D., Tkin. Coll., Tokonto. 



(Specimens exhibited before the Canadian Institute, Dec. 17th, ]854.) 



We devoted one fine morning to a hasty visit to Rice 

 Lake to fish : we spent about three hours there, and on our 

 return we directed our attention to collecting things microsco- 

 pical. 



A gentleman, who accompanied us, had long resided at the 

 Lake, and described a peculiar jelly-looking substance which 

 he had seen on a submerged stick, and undertook to row us to 

 the very spot; he did so, and introduced us to a magnificent 

 Polypidom of Plumatella 1 It measures eight inches by five 

 inches, and necessarily contains many thousands of Polypes. 



The Plumatella is a Bryozoou, or Ciliobranchiate Polype, that 

 is to say its tentacles, or arms, are covered with vibratile cilia. 

 Not being provided with a microscope, we could not make an 

 examination on the spot, but had to convey the specimen 

 home to Toronto ; and here, even, circumstances prevented us 

 working at it until nearly too late, as the animals died, and 

 almost immediately decomposed. From what we did see, 

 however, there is some reason to conclude that this species 

 differs from the European animal, not merely in the form of 

 the cells, but in the animal itself, which is certainly larger, and 

 appears to possess a much greater number of tentacles. 



In making microscopical examinations of thin slices of this 

 Polypidom, we were struck with the appearance of a great 

 number of bodies such as represented at a, and for 

 some time we necessarily concluded that we were gazing upon 

 the ova of the Polype, in various stages of developement, as 

 shewn at b and c, in the same figure. The central mass is 

 entirely, and densely dark, while the narrow, somewhat trans- 

 parent margin seen at a, is remarkably cellular, being composed 

 entirely of hexagonal cells, of much regularity in their form 

 and size (d). These cells are again seen in i, at/, where, also. 



we see developed six hooks — three at either end ; at c, the 

 hooks appear to have attained their maximum developement. 

 In examining the specimens by direct light, (as opaque objects), 

 VoL.'lII.,No. 9, April, 1855. 



the C3lls are seen to be continuous over the entire surface. 

 The presence of cells ofiers no objection to the animality of 

 these bodies, whilst the hool-s remind one so forcibly of the 

 ovum of Cristatella mucedo, (a fresh water polype) as fiinired 

 by the late Sir J. G. Dalyell, Part., Raspail, Cornelius Varley, 

 that it left little doubt these were the indubitable ova of 

 the Pkimatella, wh'in, presently, several of the mature bodies 

 appeared, their surface being more or less covered with 

 corpuscles of starch, as shewn at g. cj. in c — this was at 



C 



once conclusive of their vcgetahlc character, and they neces- 

 sarily resolve themselves into a new species of Xanthidium. An 

 enlarged corpuscle of starch is shewn at e. 



As compared with all other known species of Xanthidia, 

 these are remarkable for the possession of a membrane, of 

 inconceivable transparency and delicacy icyisnj tht hooks, and, 

 it is just possible that other species, if seen in a sufficiently 

 fresh state, would also present a membrane of like tenuity ; 

 altogether, one cannot but regard these specimens as throwing 

 much liiT-ht on the true structure and affinities of such bodies 

 in general, whose history has been hitherto involved in much 

 obscurity. 



A 



111 visiting the Ilumbcr Bay a new uiJir i 

 awaited us, in the form of very iiiinuto (^iiiicrosc(i| 

 A represents one of these singularly beautiful pla 



if beauties 



)ii-al) alg;e. 

 nts, which 



