GROWTH AND SEXUAL GENESIS. 4'U 



further factor which here complicates the result the age at 

 which sexual genesis commences. The smaller Phsenogama 

 are mostly either annuals, or perennials that die down 

 annually ; and seeding as they do annually before their 

 deaths, or the deaths of their reproductive parts, it results 

 that in the course of a year, each gives origin to a multitude 

 of potential plants, of which every one may the next year, if 

 preserved, give origin to an equal multitude. Supposing but 

 a hundred offspring to be produced the first year, ten 

 thousand may be produced in the second year, a million in 

 the third, a hundred millions in the fourth. Meanwhile, 

 what has been the possible multiplication of a large Phoe- 

 nogam? While its small congener has been seeding and 

 dying, and leaving multitudinous progeny to seed and die, it 

 has simply been growing ; and may so continue to grow for 

 ten or a dozen years without bearing fruit. Before a Cocoa- 

 nut tree has ripened its first cluster of nuts, the descendants 

 of a wheat plant, supposing them all to survive and multiply, 

 will have become numerous enough to occupy the whole 

 surface of the Earth. So that though, when it begins to 

 bear, a tree may annually shed as many seeds as a herb, yet 

 in consequence of this delay in bearing, its fertility is incom- 

 parably less ; and its relatively-small fertility becomes still 

 further reduced where, as in Lodoicea Sechellarum, the seeds 

 take two years from the date of fertilization to the date of 

 germination. 



340. Some observers state that in certain Protozoa there 

 occurs a process of conjugation akin to that which the 

 Protopliyia exhibit a coalescence of the substance of two 

 individuals to form a germ-mass. This has been alleged 

 more especially of Actinophrys. The statement is question- 

 able ; but if proved true, then of the minute forms that 

 appear to be more animal than vegetal in their characters, 

 some have a mode of sexual multiplication by which the 

 parents are sacrificed bodily in the production of a new 

 VOL. IT. 19 



