Heredity. 147 



every reproduction into an ontogenetic portion, out of 

 which the individual is built up, and a phylogenetic 

 portion which is reserved to form the reproductive 

 material of the mature offspring. This reservation of 

 the phylogenetic material I described as the continuity 

 of the germ protoplasm" . . . " Encapsuled in the 

 ontogenetic material, the phylogenetic protoplasm is 

 sheltered from external influences, and retains its spe- 

 cific and embryonic characters." 



Brooks notes that, in papers published in 1876 and 

 1877, he had also suggested the notion of germinal 

 continuity, and the conception is clearly expressed in 

 his work already quoted: "The ovum gives rise to 

 the divergent cells of the organism, but also to cells 

 like itself. The ovarian ova of the offspring are these 

 latter cells, or their direct unmodified descendants. The 

 ovarian ova of the offspring share by direct inheritance 

 all the properties of the fertilized ovum." 



The important theory of Galton now requires notice. 

 Two preliminary notes are requisite. Galton was ex- 

 tremely doubtful in regard to the genuine transmission 

 of acquired characters. It was to account for the pos- 

 sible faint inheritance of some of these that he admitted, 

 as a subsidiary hypothesis, a limited amount of pan- 

 genesis. In the second place, it is needful to notice 

 Galton's term " stirp", which he used to express the 

 sum total of the germs, gemmules, or organic units of 

 some kind, which are to be found in the newly-fertilized 

 ovum. 



(1) Only some of the germs within the stirp attain 

 development in the cells of the "body". It is the 

 dominant germs which so develop. 



(2) The residual germs and their progeny form the 

 sexual elements or buds. The part of the stirp devel- 

 oped into the "body" is almost sterile. The continuity 

 is kept up by the undeveloped residual portion. 



(3) The direct descent is not between body and body, 

 but between stirp and stirp. "The stirp of the child 

 may be considered to have descended directly from a 

 part of the stirps of each of its parents; but then the 

 personal structure of the child is no more than an im- 



