LINNEAN SOCIETY OP LONDON. IxV 



knowledge of the animal kingdom, as well as accurate and detailed 

 observation of some of its branches. And I learn from Professor 

 Huxley that, though still (luite a young man, he is already well 

 known for good work in the investigation of some of the lower 

 branches of animals, especially lladiolaria. 



I do not profess to have studied this work in detail ; much of it 

 relates to animal forms which aro out of my special line : it may 

 therefore seem presumptuous in me to offer any opinion upon it ; 

 yet there are a few of its general features well worthy of the con- 

 sideration of all naturalists, upon which I might be allowed to 

 make a few observations. The points I particularly allude to are : — 

 1st, the general division of the science; 2nd, the relation of 

 organisms to inorganic bodies; 3rd, the supposed mathematical 

 fundamental forms of organisms. 



Haeckel's first division of the science, irrespective of any special 

 class of beings studied, is into Anatomy and Morphogeny, one 

 volume being devoted to each. To Anatomy he gives a widely 

 extended meaning, including everything relating to outward form of 

 the individual or its parts, as well as their inner structure, in a 

 complete state ; whilst Morphogeny relates to the development of 

 organisms. Anatomy is subdivided into promorphology or the study 

 of outward form, and tectology or that of inner structure ; and in 

 Morjihogeny he distinguishes the development of the individual and 

 that of the phylon or race, a new name introduced to designate the 

 succession of individuals supposed to have descended from any one 

 of the few supposed primitive simple forms. 



Further, in subdividing any of these branches, he rejects the old 

 vague distinctions of histology, organology, and general morphology, 

 and proposes six form-individuals, which he elsewhere terms dis- 

 ciplines, as separate subjects of study in the case of all organisms 

 where they all exist at successive stages of development. It would 

 be useless to translate here his definition of a form-individual, as it 

 would require some study to understand it, and their enumeration 

 will give at once a clearer idea of his meaning. They are : 



1. Plastides or cytodes and cells, cytodes being elementary par- 

 ticles without a nucleus, whilst cells proper are furnished with a 

 nucleus. 



2. Organs, compounded of cells in various degrees of complexity, 



3. Antimeres, or homotypical laterally opposed parts — the rays 

 . of lladiolaria, the symmetrical halves of bilateral animals. 



4. Mctamcros, or hemodynamic, consecutive parts — the segments, 

 LINN. PRoc. — Session 1867-68. f 



