1855.] Passing visits to tb^ rice lake, riveii humbek, ueenadier's pond, &c. 



2oa 



Strangely enough, the Island ponds, opposite Toronto, 

 favored us with specimens, also silicious, and bearing nearer 

 affinity to the fossils of Barbadoes than any yet discovered, so 

 far as we know. 



B, represents one of these animals (?) — it was alive 

 when we examined it, and moved about ♦he licld with a gliding 

 motion. At a, is represented a limb which possesses a joint, 

 by means of which it can open and shut at pleasure ; li, shews 

 a floculent mass, which gave an idea ai'/ood, while <■ represents 



a curious trumpet-shaped termination which, from the fre- 

 quency of finding them, appears to be easily detached : finally, 

 the entire surface is covered with very minute tubercles. 



All the specimens here described, have been converted into 

 permanent preparations, and it is hoped that the above 

 description of them will prove interesting to the members of the 

 Canadian Institute. 



ADDITIONAL OBSERVATIONS BY .1. EOVELL, M.D. 

 The Bear. 



Within the last few weeks I have had the opportunity of 

 examining the alimentary canal of the brown Bear of this Pro- 

 vince, which presents some interesting points for observation. 



First, the pesophagus. — This tube on being submitted to 

 microscopic examination, furnishes an exception to the general 

 rule with reference to the form of muscular fibre found in it. 

 In works on Physiology and Anatomy, it is stated that striped 

 muscular fibre exists in the upper third only ; the lower portion 

 possessing non-striped fibre.* Messrs. Todd and Bowman, how- 

 ever, observe, " In some specimens from the human subject, 

 we have failed in detecting any (striped fibre) in the lower 

 half of that tube, either in the circular or longitudinal layer ; 

 but in another example we have found them to within an inch of 

 the stomach." Beale, in his Clinical Medicine, notices 

 the presence of striped muscle in the resophagus of tench. 

 In the Bear I find that striped fibre exists throughout 

 the whole tube, terminating in an abrupt line with its 

 convexity towards the stomach. In the rest of the .stomach 

 and intestines there is ordinary plain fibre. The villi of the 

 intestines are very varied in form. In the duodenum they are 

 exceedingly elongated and densely packed ; injected with 

 chromate of lead their vascularity is beautifully shown, and the 

 arrangement of the vessels at the base of each villus is dis- 

 tinctly brought out, and it appears that the vessels of all the 

 villi are in communication ; thus, supposing six villi placed 

 together, the vessels at the base present the following arrange- 

 ment : — 



^^ 



^r 



C 



In this portion of the intestinal canal, they also present broad 

 bases and very obtuse apices. In the ilium they are consider- 

 ably smaller, and cluster in greater numbers on and around the 

 raised margins of the Payercan Patches. In the large intes- 

 tine the villi have disappeared, and, as in other animals, have 

 more the appearance of a stomach ; the net work of beautiful 

 capillaries, rendering the organ intensely vascular. Here, how- 

 ever, is another peculiarity noticed,— along the whole length of 

 this large tube an unbroken chain of glands, about one ((uarter 

 of an inch in width, runs, having short villi covering the sur- 

 face. This arrangement gives one the idea that the plain sur- 

 face of the intestine may perform the oflice of a second stomach, 

 whUe the long chain of glands is a real excretory apparatus. 



The IiOl>8lcr. 



There is one other subject which I desire to bring before the 

 Institute, with the view to obtain information. While engaged 

 in dissecting a lobster, my attention was jiavticularly directed 



* I cannot procure a reference to Mr. Gulliver's papers. 



