430 



LAWS OF MULTITLICATION. 



Thus, as quoted by Dr. Carpenter, Fries says — " in a single 

 individual of Reticularia maxima, I have counted (calculated ?) 

 10,000,000 sporules." It needs but to note the clouds of 

 particles, so minute as to look like smoke, which ripe puff- 

 balls give off when they are burst, and then to remember 

 that each particle is a potential fungus, to be impressed with 

 the almost inconceivable powers of propagation which these 

 plants possess. The Lichens, too, furnish examples. 



Though they are nothing like so prolific as the Fangi (the 

 difference yielding, as we shall hereafter see, further support 

 to the general argument), yet there is a great production of 

 germs, and a proportionate sacrifice of the parental indi- 

 viduality. Considerable areas of the frond here and there 

 develop into apothecia and spermagonia, which resolve them- 

 selves into sperm-cells and germ-cells. Some con- 

 trasts presented by the higher Algce may also be named as 

 exemplifying the inverse proportion between the size of the 

 individual and the extent of the generative structures. While 

 in the smaller kinds relatively large portions of the fronds are 

 transformed into reproductive elements, in the larger kinds 

 these portions are relatively small : instance the Macrocystis 

 pyrifern, a gigantic sea-weed, which sometimes attains a 

 length of 1,500 feet, of which Dr. Carpenter remarks — 

 " This development of the nutritive surface takes place at 

 the expense of the fructifying apparatus, which is here quite 

 subordinate." 



When we turn to vegetal aggregates of the third order of 

 composition, facts having the same meaning are conspicuous. 

 On the average these higher plants are far larger than 

 plants of a lower degree of composition ; and on the average 

 their rates of sexual reproduction are far less. Similarly if, 

 among Acrogens, Endogens, and Exogens, we compare the 

 smaller types with the larger, we find them proportionately 

 more prolific. This is not manifest if we simply calculate 

 the number of seeds ripened by an individual in a single 

 season; but it becomes manifest if we take into account tho 



