4: ELEMENTS OF COMPARATIVE ZOOLOGY. 



sharpening instruments ; a pair of bone forceps * for cut- 

 ting hard substances; a hypodermic syringe and other ap- 

 paratus for injection (see Appendix) ; a skeleton of at least 

 one representative of each great group of Vertebrates ; and 

 at least one good compound microscope. 



MATERIALS FOE DISSECTION. 



The forms selected for study are, so far as possible, such 

 as can readily be obtained in any locality by taking a little 

 pains at the proper season. There are, however, certain 

 groups of animals which occur only in the sea, and repre- 

 sentatives of these must be obtained from the shore. 

 These marine forms selected are Embryo Dogfish (Squalus), 

 Squid (Loligo), Sea-urchin (Arbacia), Starfish, Sea-anemone 

 (Metridiiim), Hydroid (Pennaria), and Calcareous Sponge 

 (Grantia). The series may be obtained from dealers f at 

 a cost not exceeding sixty cents per student. Orders for 

 these should be placed in the early summer, so that no 

 difficulty or delay may occur later. Much of the other 

 material may be obtained when wanted, but such as can- 

 not be had in the colder months frogs, tadpoles, snakes, 

 turtles, crayfish, insects, earthworms, etc. should be col- 

 lected in the summer and preserved in alcohol or formol J 



* In place of the expensive bone forceps of dealers in surgical in- 

 struments one can use the oblique-cut pliers to be purchased at any 

 hardware dealer's. 



f Supply Department, Marine Biological Laboratory, Wood's Hole, 

 Mass. 



Prof. H. W. Conn, Middletown, Conn. 



F. W. Walmsley, Bridgeton, N. J. 



Leland Stanford University; Stanford University P. 0., California. 



These dealers issue price-lists. 



| See Appendix for preservative fluids and methods 



