COSMIC PHILOSOPHY 



gradually led to the true mollusks ; while on the 

 other hand, the tunicata, of which the ascidian or 

 " pitcher " (the primitive " tadpole " of unsci- 

 entific ridiculers of Darwinism) is the most fa- 

 miliar form, lead us directly to the vertebrates. 1 

 At first the vertebrata are all fishes, if such mol- 



1 Kowalewsky has discovered some wonderful likenesses 

 between the embryonic development of the ascidian and that 

 of the amphioxus or lowest known vertebrate. Of all the 

 " missing links," the assumed absence of which is so persist- 

 ently cited by the adherents of the dogma of fixity of species, 

 the most important one would here, appear to have been 

 found ; for it is a link which connects the complex and highly 

 evolved vertebrate with a very lowly form which passes its 

 natural existence rooted plant-like to the soil, or rather to the 

 sea-bottom. The ascidian cannot, indeed, be regarded as typi- 

 fying the direct ancestors of the vertebrata. It is a curiously 

 aberrant and degraded form, and its own progenitors had 

 doubtless once " seen better days." In its embryonic state 

 it possesses a well-marked vertebral column, and it behaves in 

 general very much as if it were going to grow to something 

 like the amphioxus. But it afterwards falls considerably short 

 of this mark. Already in early life its vertebras begin to become 

 "rudimentary " or evanescent ; and when fully matured, it 

 stops swimming about after its prey, and, striking root in the 

 sub-marine soil, remains thereafter standing, with its broad 

 pitcher-like mouth ever in readiness to suck down such organ- 

 isms floating by as may serve for its nutriment. That verte- 

 brae should be found in the embryo of such an animal is a most 

 interesting and striking fact. It would seem to mark the asci- 

 dian as a retrograded offshoot of those primitive forms on the 

 way toward assuming the vertebrate structure, of which the 

 more fortunate ones succeeded in leaving as their representative 

 the amphioxus. 



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