1889.] MICROSCOPICAL JOURNAL. 11 



BIOLOGICAL NOTES.* 



Color of Flowers and Fruits. — In the December number of the 

 A?n.Jour. Sci. Prof. Goodale reviews the. work of Courchet, Schim- 

 per, and previous observers upon the origin of color granules in flowers 

 and fruits. To the granular proteid bodies found in the living proto- 

 plasm the name plasts or plastids has been given, and they are termed 

 leucoplasts, chloroplasts, or chromoplasts, as they contain no color, are 

 colored with chlorophyll, or have some other coloring matter. The 

 chromoplasts always originate from either leucoplasts or chloroplasts. 

 Blue, violet, and rose tints are generally due to colored cell sap while 

 yellow and orange tints are chiefly due to crystals or solid masses which 

 originate from the chromoplasts. 



To Remove the Gelatinous Covering of Amphibian Eggs. — 

 Prof. C. O. Whitman (Am. Nat., vol. xxii, p. 857) recommends the use 

 of a 10% solution of sodium hypochlorite diluted by five or six times its 

 volume of water. The eggs are immersed, after hardening, only long 

 enough to dissolve the covering. Necturus eggs required about five 

 minutes. 



Clover Rust. — Prof. L. M. Underwood reports (Bot. Gaz., vol. 

 xiii, p. 302) the appearance of this rust, Uro?nyces trifolii, upon Tri- 

 folium pratense in the vicinity of Syracuse the past summer. The 

 damage done to the clover crop he estimates from 5 to 20 per cent, of 

 the value of the crop. As this is its first reported attack upon the red 

 clover in this country, it is a question of special interest to agricultur- 

 ists as well as botanists. 



Pores of Libriform Tissue. — Dr. Emily L. Gregory, in the Bul- 

 letin of the Torrey Botanical Club (vol. xiii, p. 197), has an elaborate 

 discussion of the relation of the bordered pores in the cells of libriform 

 tissue to the flow of the sap of plants. The tissues of representatives 

 of 64 families of plants were examined, and the author finds the arrange- 

 ment of these pores such as to lead to the conclusion that they are the 

 most important means of sap flow, especially in that portion of tissue 

 lying next the cambium layer. The pores in a large number of cases 

 are on the tangential side of these cells, thus facilitating the supply of 

 sap to the newly forming tissues of early summer. 



Poison Organs of the Mosquito. — Prof. Geo. Macloskie describes 

 {Am. Nat., vol. xxii, p. S85) the poison glands and duct of the mos- 

 quito ( Culex) . He has been able, by staining and dissection, to show 

 that the poison gland is one of three minute glands (the others being 

 ordinary salivary glands) on each side of the head, and connected with a 

 minute duct which traverses the length of the long pointed piercer which 

 forms an important portion of the mouth parts of the mosquito. The 



* This department is conducted by Prof. J. H. Pillsbury. 



