Ixvi PROCEKUINaS OF THE 



ringa, or zonitcs of Vertebrata and Articulata, the articles or in- 

 ternodes of plia3nog"amous plants. 



5. Persons or Prosopes — individuals in the limited sense of the 

 word as to the higher animals, buda or gemmae of plants and 

 Coelenterata. 



6. Corms, stocks, or colonies — compound organisms, such as trees 

 and perennial plants, chains of Salpaj, stocks of Polypes, &c. 



These six forms, he tells us, are so many grades of development, 

 throiigh which every individual has to pass to attain the higher 

 ones, commencing with the ovum in its primitive state as a simple 

 cell and passing successively through the following ones. The cells 

 multiply and are developed into organs, the sets of organs become 

 arranged into antimeres, these are- divided into metamercs, and 

 constitute the complete individual of the fifth grade, or are further 

 developed into the compound corm of the sixth ; and any one grade 

 may be the permanent form of an individual through life. Thus 

 some of the Algce, and others of the lowest forms of organisms, are 

 arrested at the first grade of the simple cell ; the majority of the higher 

 animals are complete with the fifth form ; and the majority of plants 

 and Coelenterata attain the sixth, others again, according to flaeekel, 

 being arrested in the state of more or less complex organs, antimeres 

 or metameres. 



There seems no doubt that this logical distribution of the subject, 

 carefully studied in many of the points of view in which Ilaeckel 

 has worked them out, may bo of considerable service in investiga- 

 ting the complicated structure and relations of the liigher organisms, 

 although there arc many of the details which appear to mo open to 

 criticism as more speculative than founded upon fact. The clear 

 distinction between the fifth form or the individual in the ordinary 

 sense of the term, and the more compound corm or sixth form, will 

 serve especially to dispel much of the speculative obscurity in which 

 the discussion as to what is an indiAddual has been involved. The 

 importance of the separate study of antimeres and metameres as 

 different stages of development may, on the other hand, be too 

 much insisted upon by Ilaeckel. In most cases their development 

 appears to me to be rather simultaneous than consecutive, and that 

 we may just as well say that the antimeres are made up of metameres 

 as that the metameres are made up of antimeres. But perhaps these 

 forms have acquired more than usual importance in Haeckel's mind 

 from their bearing upon his reduction of the complicated forms of 

 organisms to mathematical types. 



