32 DEVELOPMENT OF THE TADPOLE. 



of which only have been given in the diagrams. In Fig. 2 we also 

 find a small portion of the eye, with its nerves, as well as the organ 

 which up to the present has been called the pro-renal ducts, but 

 which may possibly turn out to be also an indication of the ovaries. 

 But more on this point m the future, if our Editor thinks these 

 articles worth continuing. 



EXPLANATION OF PLATE lY. 



b., brain; nc, notochord ; la., lungs; Jp., lips; /., hver ; 

 h., heart ; h.v., ventricle of heart ; pa., pulmonary artery ; prd., pro- 

 renal-ducts ; oc, optic capsule; noc, nerves of ditto ; ms., muscles; 

 m. , mouth ; br.a. , branchial arch ; cL , claspers ',s.g., saUvary glands x 50. 



Collecting Diatoms. 



In an interesting article in the Bulletin of the Torrey Botanical 

 Club, Dr. C. Henry Kain discusses the " Diatoms of Atlantic 

 City and Vicinity." Speaking of the bright brown patches of 

 diatoms frequently seen covering the surface of the mud, he 

 recommends that they be collected in the following manner : — 

 Half fill a bottle with water. Touch one of these brown patches 

 lightly with the tip of the finger, and the diatoms will adhere ; 

 then place the finger over the mouth of the bottle, and shake. 

 The diatoms are, of course, washed off, and remain. By repeat- 

 ing this process, again and again, the water finally becomes quite 

 brown. By the time the collector reaches home, the diatoms will 

 have settled to the bottom, and the water may be poured off, and 

 the diatoms cleaned. It is worth while to examine under the 

 collecting lens every prominent patch of brown mud, for many pure 

 gatherings of quite different species may often be collected 

 within a few feet of each other. 



