19G Prof. Cavl Glaus on the 



extensive, indeed almost unlimited, use of his skill in making 

 new and suitable names, is certainly intelligible from the fact 

 that he possesses this faculty in a very high degree and has 

 developed it, by many years' practice, into a speciality, in 

 which at present no other naturalist can hope to equal him. 

 But, although it cannot be denied that the introduction of 

 new and appropriate names has many advantages, and is 

 especially indispensable for the sake of conformity in the 

 schematization of theory and system, it is, however, indis- 

 putable that by the continual accumulation of synonyms it 

 leads to a nearly unlimited complication of nomenclature, 

 causes much confusion, and instead of facilitating investiga- 

 tion renders it more difficult. It is therefore only in place 

 when moderately exercised where the conditions absolutely 

 require it, but when immoderately done without absolute 

 necessity decidedly mischievous, and to be rejected at once 

 when by it old, equally good names, which have become 

 historical by the personality of meritorious authors, are dis- 

 placed and removed from science. 



However, our knowledge of forms has been extraordinarily 

 enlarged by Haeckel's work, inasmuch as out of 240 species 

 more tl)an 60 were previously unknown, and these for the 

 most part belong to new and interesting genera. By this 

 astonishing enrichment of the materials the system must also 

 have undergone a corresponding complication of form and 

 abundance of divisions, and besides new genera new categories 

 of higher rank, especially families and subfamilies, have had 

 to be established. Unquestionably the special descriptive 

 part, which is also of much greater extent, possesses a much 

 higher value than the general or "philosophical" part, which 

 is more aphoristically treated in the short introductory chap- 

 ters, and which is intended to found the Medusome-theory 

 and the system established upon it. Whether in the former 

 the author has everywhere hit upon the right course and has 

 not often gone too far may even now be justly doubted, and 

 will be decided in the future by later investigations. There 

 are numerous novelties in connexion with the division of pre- 

 existing genera into two or more, and, indeed, on the ground 

 of trifling distinctions scarcely applicable as generic characters. 

 As examples may be cited the division of Physalia into Phy- 

 salia and Caravella and of Aloj)leota into AlopJeota and 

 Arethusttj as also the establishment of two subfamilies asso- 

 ciated therewith ; further the breaking up of Rhizophysa by 

 its different species into the genera Aurophysa, Cannophysa, 

 Linophysa, Nectophysa, Fneianoj)hysa, and Rhizophysa^ and 



