410 P0LYZ(3A. 



Whatever else the study of the Polyzoa and its long family 

 history may teach, it proves, at least to my satisfaction, that 

 Lamarck's theory of evolution (as I have always understood it) is 

 not supported by what are now well-known facts. We are, how- 

 ever, deeply indebted to Lamarck as the first naturalist who sug- 

 gested an origin of species apart from a special creative act. An 

 organism of such simple construction as a Polyzoon, with its close 

 method of reproduction, could scarcely be expected to develop 

 into a being very greatly differentiated from the earliest type. It 

 must be borne in mind that in sexual arrangement this organism 

 is hermaphrodite. In the vegetable kingdom, genera which are 

 hermaphrodite, or close fertilising, usually contain a much smaller 

 number of species than those which are mainly or solely propa- 

 gated by cross-fertilisation. 



The OrchidacecE, with a few exceptions, are dependent upon 

 cross-fertilisation, and in some species upon the services of highly- 

 specialised insects, for the performance of this essential operation. 

 Nevertheless, this well-known order of plants is said to contain 

 upwards of 30,000 species. In accounting for the comparatively 

 small variation in structure during such immense periods of geo- 

 logical time, we must remember Darwin's axiom that '' there is 

 no evidence of the existence of any law of necessary develop- 

 ment." This eminent naturalist"^ further observes : — 



" As the variability of each species is an independent property, 

 and will be taken advantage of by natural selection, only so far as 

 it profits each individual in its complex struggle for life, so the 

 amount of modification in different species will be no uniform 



quantity These principles come into play only by 



bringing organisms into new relations with each other, and in a 



lesser degree with the surrounding physical conditions 



Some forms have retained nearly the same character from an 

 immensely remote geological period, so certain species have 

 migrated over vast spaces, and have not become greatly, if at all, 

 modified." 



Bearing in mind the simple structure of the Polyzoa, their 

 reproductive processes, the probability that their very insignifi- 

 cance has in some degree saved them from the severe struggle for 

 * Darwin's Origin of Species by tneans of Natural Selection, p. 618. 



