1898 33 



WINTER LECTURES, 1897-8. 



A novel and most interesting feature of the lecture course 

 of the past winter was a series of three practical demonstrations 

 given by the President.of the three most important divisions of the 

 Animal Kingdom, illustrated by A Fish, a Bird, and a Mammal- 

 All who were fortunate enough to attend these lectures were 

 charmed at the skill shown by the lecturer in dissecting the 

 specimens and explaining the uses of the various organs exposed 

 by the dissecting knife at the same time that they were pointed 

 out on enlarged charts hung on the walls. At all of these 

 lectures, specimens and a fine selection of lantern views were 

 shown, which added largely to their educational value. 



I "A FiSPl." — In his first lecture (Feb. 8th) Professor Prince 

 described the main features in the form and structure of such a 

 typical fish as the Pickerel or Dore. The pointed head, the 

 tapering tail and the powerful fins, especially the breast fins, 

 were referred to. The teeth are sharply hooked and not adapted 

 for mastication, but rather for seizing and holding the prey 

 selected for food. Digestion, on account of the powerful sol- 

 vents secreted in the alimentary canal, is rapid. In the main 

 fold or bend of the intestine the ductless spleen lies. It is an 

 organ probably connected with the formation. of blood. There 

 is no pancreas (or sweetbread) in fishes, but the bunch of finger- 

 like organs attached to the stomach, called the pyloric caeca, 

 performs the same function in connection with digestion. By 

 means of the red gills, through which the blood circulates, the 

 pure air dissolved in water is breathed and oxygenates the 

 blood The circulation in fishes is very simple. The two- 

 chambered heart, situated far forward, almost beneath the chin, 

 drives the blood by the central ^aorta and afferent branchial 

 arteries to the gills, where it passes along the fine comb-like fila- 

 ments and returns to the dorsal aorta, which carries it along the 

 underside of the backbone and thence all over the body. It 

 collects again in the two large veins which empty into the ductus 

 cuvieri, and thence into the auricle of the heart. There is thus 

 no separated double circulation in fishes. The hearing of fishes 



