466 Prof. S. Apjlthy on 



appear to liim to be greater than, when considered from the 

 comparative stan(li)oint, they actually are. 



In what follows I only hope to apply to an interesting 

 concrete case nothing but what is well known and generally 

 admitted, while venturing to add thereto certain reflections of 

 my own. 



" It is a well-known fact," says Frenzel in his second paper 

 {loc. at. p. 577*), " that between unicellular and multicellular 

 animals there hitherto stretched a gulf which was wider than 

 that between the vegetable and animal kingdoms ; for indeed 

 the two latter, in spite of the advances which we have made 

 in knowledge, are even to-day hardly separable from one 

 another," But the further our knowledge progresses the less 

 will such a separation be possible, and the less moreover shall 

 we consider it to be necessary : the animal and vegetable 

 worlds have been developed in two different directions from a 

 common basis, the non-nucleate Protoblasts. I totally dis- 

 believe that it is permissible to institute such comparisons in 

 the natural sciences. A gulf, if it is once present, can be 

 neither smaller nor greater than any other. 



Between animals and plants a gulf might well exist ; but 

 happily it does not. It is nevertheless only in relatively 

 quite recent times that our store of facts has been so far 

 enriched as to render it possible to bridge over the gulf, 

 which, from the standpoint of earlier knowledge, was only 

 too evident. It is possible that, among the forms at present 

 existing, there is a gulf between Protozoa and Metazoa ; it is 

 possible, nay even very probable, that it does not really exist 

 at all, and that our array of facts only needs to be further 

 amplified in order to bridge it over. The transition also from 

 the unicellular to the multicellular plants is to-day quite a 

 gradual one: why should it be otherwise from the unicellular 

 to the multicellular animals ? Frenzel contributes a very 

 considerable pillar to the bridge, and withal exerts himself, in 

 developing his paper, to make the gulf appear deeper and 

 broader than it is. Our science docs not deserve such an 

 extremely pessimistic conception of its present position ; 

 although in a general way I consider pessimism — but without 

 relapsing into resignation and exclaiming ^'' Ignorahimus " ! — 

 active pessimism, to be more fruitful than activity in an 

 exaggeratedly optimistic direction. Frenzel, however, also 

 overlooks stones wliicli are already in existence for the 

 building of the future bridge between Protozoa and ^letazoa. 



Frenzel moreover does the modern zoologist injustice when 



* Ann. & Map. Nat. Hist. loo. cif. p. 7'.>. 



