GENERAL CLASSIFICATION 139 



attributing to these organs a nature and functions that do not really 

 belong to them (as has happened to so many botanists who imagined 

 they saw male and female organs in nearly all the cryptogams), then 

 the following result ensues : 



1. That we must no longer refer the beginning of the nervous 

 system to the insects ; 



2. That this system must be regarded as existing in a rudimentary 

 form in the worms, radiarians and even in the sea-anemone, the last 

 genus of the poljrps ; 



3. That this however is no reason why all the polyps should possess 

 the rudiments of this system ; just as it does not follow that because 

 some reptiles have gills, therefore they must all have them ; 



4. Finally, that the nervous system is none the less a special organ, 

 not common to all living bodies ; for, not only is it absent in plants, 

 but it is absent also in some animals. As I have shown the infusorians 

 cannot possibly have it, nor assiiredly can it be possessed by the 

 majority of polyps ; thus we should seek it in vain in the hydras 

 which belong nevertheless to the first order of polyps, that, namely, 

 which is nearest to the radiarians, since it comprises the sea-anemones. 



Thus, whatever truth there may be in the facts named above, the 

 considerations set forth in this work as to the successive formation 

 of the various special organs hold good at whatever point in the animal 

 scale each of these organs begins ; and it remains true that the various 

 faculties of animals only take their origin from the existence of the 

 organs underlying them. 



TABLE OF RADIARIANS. 



Oedbr 1. — Soft Radiabians. 



[Various Coelenterates, exclusive of Anthozoa. H. E.] 



Bodies gelatinous ; soft, transparent skin without jointed spines ; 

 no anus. 



Stephanomia. Physsophora. 



Lucemaria. Physalia. 



Velella. Aequorea. 



Porpita. Rhizostoma. 



Pyrosoma [Tunicate. H. E.]. Medusa (jelly-fish). 

 Beroe. 



OeDEK 2. ECHINODERM BaDIABIANS. 



Opaque, crustaceous or coriaceous skin, provided with retractile tuhercles, or 

 spines articulated on tubercles, and pierced with holes in series. 



(1) SteUerides. Skin not irritable, but mobile ; no anus. 

 Ophiura (brittle-star). 

 Asterias (star-fish). 



