50 PENIKESE. 



exercises were postponed, in perfect good nature, 

 while Professor Putnam explained to us the differ- 

 ence between it and an immense sand-shark, over 

 which one of the scholars was just then working. He 

 told us, that the sharp tubercles of the skate were 

 identical with the small, rough ones of the shark;that 

 the skate was higher in its position in the class than 

 the shark, as its embryo passes through the form of a 

 shark before becoming an adult skate; that if one 

 were to flatten a shark they would obtain the general 

 appearance, in form, of the skate; a fish having spir- 

 acles, indicates that it lives near the bottom of the 

 water; that neither the shark nor the skate possessed 

 scales, and were, therefore, of a different order from 

 that of the majority of fishes; and that the character 

 and structure of the scales of fishes determined, to a 

 large extent, the relative position not only of whole 

 groups of fishes but even of many individuals in each 

 group. 



Later, in the same day, Professor Packard added 

 largely to our stock of information. Many of us had 

 sought to study up the subject of Animalculae, in fact 

 all of us were more or less interested in it; and forth- 

 with, jars, bottles, and dishes of various sorts were 

 filled with water, and large quantities of the very best 

 material that could be obtained, for breeding and 

 keeping them. Our hitherto rusty microscopes now 

 fairly gleamed, in expectation of the marvels soon to 

 be laid open, through them, to our wondering gaze. 

 Professor Packard knew all about such things. He 

 told us to "search in fresh water, rain water, water 

 abounding in mosses, and marine pools, for our sub- 

 jects of study and investigation." Somebody brought 

 in to us specimens of worms and small parasitic crus- 

 taceans, and of where and how to find others and 

 how to preserve them, he told us: "You will find 

 them in dissecting fishes and reptiles, in nearly every 

 portion of the body and in the viscera; tape and sun- 

 dry specimens of minute worms and flukes are found 

 in the body. Place them at first in weak and then 



