448 NOTES AND MEMORANDA. 



the apex is carried up above the surface of the soil. These 

 products of the modification of the root-cells the authors 

 name liypnosporanges. They represent the so-called Botry- 

 dium Wallroihii. The portion above ground is exactly 

 globular^ scarcely 0*5 mm. in diameter, dark- almost black- 

 olive-green, and not tapering downwards. For a consider- 

 able distance downwards the root is constantly unbranched, 

 and^ as said, its wall much thickened. The secondary 

 ramifications are thin-walled. Dried, the hypnosporanges 

 maintain their power of germination during the Avhole 

 year in which they originate, and, when brought into 

 water, form zoospores independently of the hour of day or 

 might. The zoospores, as in the former instances, are 

 uniflagellate, germinate, and form young plants in the same 

 manner. 



Young plants formed therefrom can increase by cell divi- 

 sion. At any point of the aerial part of the plant a pro- 

 tuberance is formed, into which a portion of the plasma 

 and of the chlorophyll collects. When the protuberance has 

 acquired the size of the mother-plant, it puts forth a colour- 

 less hyaline process, which penetrates the earth as a root. 

 The connection with the mother-plant is shut ofFby a septum, 

 and finally the two cells separate, in order to lead an inde- 

 pendent existence. Several such projections may be sinuil- 

 taneously given off, giving origin to so many daughter-indi- 

 viduals. But this process cannot be followed out under the 

 microscope ; if a young plant be placed in a drop of water 

 it becomes in the evening or at night modified into a vege- 

 tative zoosporange. 



These uniflagellate zoospores germinate in the manner 

 described when brought upon a moist substratum. On 

 ordinary garden earth or on sand they thrive but badly, 

 and form no ordinary zoosporanges. They succeed better on 

 muddy or clayey soil. In water they never germinate. 

 In this medium the zoospores, when they come to rest, be- 

 come surrounded by a double membrane and lie dormant 

 for months. If such be brought upon a clayey soil the 

 contents increase, burst the wall, and begin to form a vege- 

 tative plant. 



If the zoospores be sparingly distributed upon the soil, 

 and the whole kept under an equable degree of moisture, 

 the vegetative plants in time become ordinary zoosporanges. 

 The little plants may sometimes become directly modified 

 into hypnosporanges. 



Thus, the vegetative plants of Botrydium can be increased 

 by cell-division, directly form zoospores, become ordinary 



