226 K. E. VON BAER. — PHILOSOPHICAL FRAGMENTS. 



the same relative position as the wings in the pupa, with this 

 difference only, that they come from the head. 



For the same reason also they agree with the lateral appendages 

 of the Crustacea. Whatever sensitive properties then these 

 antennae may have, they are yet never the organs of touch, 

 smell, or hearing of Vertebrata, but sensitive cephalic wings. 



By these remarks I wish to render it intelligible, why every 

 type must be studied for itself, and possesses fundamentally 

 peculiar organs which are never to be found exactly the same in 

 any other type. In some cases, indeed, the distinction is but 

 small. The alimentary canal arises in all animals from the sur- 

 face which is turned towards the yelk. We have here the 

 smallest original difference. But in its further subdivision into 

 organs a distinction must be discoverable for the signification of 

 the separate organs ; it is indeed, as we know, often difficult to 

 recognise single divisions, as the stomach, &c. We shall suc- 

 ceed better if we determine every part only after other animals of 

 the same type. We know, for instance, how little the sexual 

 organs of the Massive series can be interpreted by those of the 

 Vertebrata. Still more striking is the tentacular system with 

 its vessels, which is found in manifold variations among the 

 Radiata, for the ciliated bands of the Beroidae and the circular 

 vessel of some (if not of all) Medusae, should perhaps be re- 

 garded as modifications of this system. In the Articulata and 

 Vertebrata, however, we are acquainted with nothing similar. 

 It is perhaps peculiar to the peripheral type. 



It will suffice merely to remark how little the notion that all 

 animals are only detached organs of Man corresponds with na- 

 ture. A few organs of the Vertebrata may, however, certainly 

 be said to contain within themselves the organs of the Massive 

 and Articulate series ; at least this appears to me to be probable 

 with regard to the organs of sense. 



I shall perhaps, in another treatise, show that even in the 

 Vertebrata, development alone can guide us in interpreting the 

 signification of the organs. 



Third CoroIuLAUy.— Application to the Affinities of Animals, 



I have above ventured to assert (Schol. V. § 1.) that the notion 

 of a uniserial succession of animals is the prevalent one, and I 



