FREE BOOKS

Author's List




PREV.   NEXT  
|<   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   101   102   103   >>  
sent the appearance of an immense candelabrum, the base of the stem being as thick as a man's body. The flower, of which a figure is given here, is about 5 inches long and wide, the petals cream colored, the sepals greenish white. Large clusters of flowers are developed together near the top of the stem. A richly colored edible fruit like a large fig succeeds each flower, and this is gathered by the natives and used as food under the name of saguarro. A specimen of this cactus 3 feet high may be seen in the succulent house at Kew.--_B., The Garden_. * * * * * HOW PLANTS ARE REPRODUCED. [Footnote: Read at a meeting of the Chemists' Assistants' Association. December 16, 1885.] By C.E. STUART, B.Sc. In two previous papers read before this Association I have tried to condense into as small a space as I could the processes of the nutrition and of the growth of plants; in the present paper I want to set before you the broad lines of the methods by which plants are reproduced. Although in the great trees of the conifers and the dicotyledons we have apparently provision for growth for any number of years, or even centuries, yet accident or decay, or one of the many ills that plants are heirs to, will sooner or later put an end to the life of every individual plant. Hence the most important act of a plant--not for itself perhaps, but for its race--is the act by which it, as we say, "reproduces itself," that is, the act which results in the giving of life to a second individual of the same form, structure, and nature as the original plant. The methods by which it is secured that the second generation of the plant shall be as well or even better fitted for the struggle of life than the parent generation are so numerous and complicated that I cannot in this paper do more than allude to them; they are most completely seen in cross fertilization, and the adaptation of plant structures to that end. What I want to point out at present are the principles and not so much the details of reproduction, and I wish you to notice, as I proceed, what is true not only of reproduction in plants but also of all processes in nature, namely, the paucity of typical methods of attaining the given end, and the multiplicity of special variation from those typical methods. When we see the wonderfully varied forms of plant life, and yet learn that, so to speak, each edifice is built with the same
PREV.   NEXT  
|<   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   101   102   103   >>  



Top keywords:

methods

 

plants

 
generation
 

processes

 

Association

 

reproduction

 

typical

 

nature

 

individual

 
present

growth

 
flower
 
colored
 
original
 
secured
 

giving

 

structure

 

immense

 

parent

 

numerous


struggle

 

fitted

 

results

 

candelabrum

 

sooner

 

figure

 

important

 

complicated

 
reproduces
 

multiplicity


special

 

variation

 

attaining

 

paucity

 
edifice
 
wonderfully
 

varied

 
fertilization
 
adaptation
 

structures


completely
 
allude
 

notice

 

proceed

 

appearance

 

details

 

principles

 

meeting

 

Chemists

 

Assistants