THE MICROSCOPE. 81 



oyster. From this nerve cord, like an ellipse, are nerve branches 

 extending everywhere. But upon this cord you notice at the pos- 

 terior part of the animal is a large ganglion, or brain. This serves 

 for the functions of respiration. On this same elliptic cord at the 

 anterior part are two ganglia, connected by a stout thread of nerve. 

 Functionally this is but one brain, like the true cerebrum, which is 

 in two hemispheres. In fact, this is the oyster's cerebrum, and is 

 set for its sensations, and whatever of psychic ability it may be en- 

 dowed with. Now here seems an anomaly, for the oyster appears 

 to be only double, and not triple, brained. Let me explain this by 

 drawing a plan of the nervous system of a pecten or scallop. You 

 see here in the anterior part is one more brain than the oyster pos- 

 sesses. This is the homologue of the medulla oblongata in man. It 

 subserves the functions of locomotion. But this mollusc while 

 young is so active in its movements as to have been called the but- 

 terfly of the sea. Hence it has a nerve mass to subserve that end; 

 whereas the oyster, once settled, never travels, hence it needs no 

 provision for such purpose. 



I hinted at the possible psychic power of the oyster, and it was 

 not a figure of speech. This lowly thing has in it some potentiality 

 of education. It can be induced to a change of conduct to accom- 

 modate itself to new circumstances. When that terrible little 

 mollusc, known as the Drill ( Urosalpinx cineria), has bored through 

 the roof of its house, intending to feed on the occupant, the oyster 

 has been known to promptly plug up the hole with nacre or mother 

 of pearl, and thus save its life by keeping the burglar out. I have 

 known an oyster to get badly broken, and to repair its house 

 thoroughly. But as we have yet to describe how it builds its house, 

 and keeps the premises in good condition, also to speak of the 

 friends it entertains and the enemies it encounters, I must hasten 

 on. — Abstracted for The Planet. 



Microscopical Examination of Drugs. — Through the liber- 

 ality of Mr. J. H. Redsecker, of Lebanon, Pa., there was offered to 

 the last senior class of the Philadelphia College of Pharmacy, and 

 has likewise been offered to the next class a prize of $20, in the de- 

 partment of Materia Medica, which prize according to the recom- 

 mendation of the Committee on Instruction, approved by the Board 



