176 



SCIENCE. 



[N. S. A'OL. XIX. Ko.474. 



cases ; though the characters it furnishes 

 may be of only specific rank, as in For- 

 sytliia and Jasminuni. 



A Plea for the Preservation of Our Wild 

 Flowers: G. B. Bessey and S. Coultee. 

 Cultivated flowers are planted and cared 

 for by man, but no one cares for the wild 

 beauties of the woods and meadow. We 

 must preserve them. It is our privilege 

 as lovers of plants to care for them and to 

 see that they are not exterminated. The 

 rarer the plant the greater the danger that 

 it will be eradicated. "WTio are the offend- 

 ers? The tourists, who lay their vandal 

 hands on everything pretty; the amateurs, 

 who^'desire to have samples of everything; 

 and some botanists who think more of col- 

 lecting specimens than of the beauties of 

 nature in the field. . At Colorado Springs 

 the once beautiful Cheyenne Canyon has 

 been made barren by the vandals, and 

 there is scarcely ^ fern or a pretty flower 

 now left in it. What shall we do about it 1 

 First of all let us talk vigorously against 

 this vandalism. Talk in season and out of 

 season, and denounce the wholesale de- 

 struction of wild flowers in the strongest 

 language possible. Then write against 

 vandalism. Do not fail to say what you 

 think through the public press. The news- 

 papers will help you every time if yon 

 call upon them. Then organize clubs and 

 guilds and societies. Do this as you please. 

 If you prefer to form a local chapter of the 

 Wild FloM'er Preservation Society well 

 and good. We shall take great pleasure in 

 helping you. But if you prefer to form 

 an independent club— do so by all means. 

 It is not how you do it ; it is only that you 

 do something. Agitate the matter persist- 

 ently and vigorously, and keep at it. In 

 this way, only, may Ave hope to save our 

 attractive wild flowers from extinction. 



Ty2:>e of the Gemis Agrostis: A. S. Hitch- 

 cock. 



In view of the fact that stable generic 

 nomenclature depends upon the method of 

 fixing the type of each genus, investigations 

 concerning the effect of various rules upon 

 different genera must be carefully worked 

 out. For this reason the history of the 

 grass genus Agrostis is presented. The 

 effect of the application of different rules 

 will be shown. 



The Morphology of Elodea Canadensis: R. 



B. Wyije. 



The pistillate flower is strongly epigy- 

 nous, the fused parts of the flower forming 

 a long floral tube which extends from the 

 sessile ovary to the surface of the water. 

 The stamens each bear two sporangia and 

 the staminate flowers at maturity break 

 loose from the stem and rise to the surface 

 of the water. The rise of these flowers is 

 aided by bubbles of oxygen. Though the 

 pollen grains are heavier than water, the 

 multitudes of spines on the exine hold back 

 the surface film, thus imprisoning enough 

 air to keep the spores afloat. The male 

 cells, which are formed in the pollen 

 grains, are very large, and during their 

 continuance in the spores remain joined 

 together. The pistillate flower opens upon 

 reaching the surface of the water and the 

 stigmas soon recurve, arching out over the 

 floral parts. Since the stigmas are im- 

 pervious to water, the weight of the flower 

 resting on them forms a depression in the 

 surface fllm. Pollen grains floating near 

 are now attracted to the flower by gravity, 

 operating through the declined surface 

 film. They approach and drop into this 

 depression in contact with the stigmas. In 

 the development of the embryo-sac, four 

 megaspores are usually formed, though six 

 were noted in one instance. The embryo- 

 sac at the two-celled stage develops an 

 antipodal pouch, in which the antipodal 

 group of nuclei is formed. The pollen 

 tube shows a marked development. Its 



