368 NATURAL SCIENCE. Nov., 



" Basis " and " foundation " also are used by some writers ; but 

 these are the renderings in English of the German word " Grundlage," 

 and express the structure upon which a superstructure is " reared," 

 not the first stage of the superstructure itself. The word " forecast " 

 has been suggested by several writers, among others by Mr. E. A. 

 Minchin. It would have been a word very suitable in the cruder 

 days of the theory of preformation ; in [these days it seems to imply 

 too close a connection in form between the " Anlage " and the 

 organ arising from the " Anlage." Professor Mark, who has discussed 

 the difficulties of the matter, employs the word "fundament"; this 

 is a neologism that few would have occasion to resent. I have 

 myself employed the word " incipium," but that offends Latinity, 

 and fundament, incipium, and primary constitutent alike fail to 

 convey the definite idea that " Anlage " is a growing structure in a 

 growing organism, or, when it is used of nuclear particles, a structure 

 of which a chief property is to grow or cause growth. The purpose 

 of the present note is to suggest as an English equivalent of 

 " Anlage " a word that would be intelligible to all English and German 

 and French biologists, and that would be understood easily by any 

 educated reader. The word I propose is "blast," a bud or point 

 of growth. The existing meanings of " blast " could cause no 

 confusion, and the word would indicate equally well the visible 

 beginnings of organs in the form of cells or cell-groups, and the 

 hypothetical precursors of these as parts of the hereditary mass. 

 The obvious existing precedent for the use of the word is the common 

 acceptation of the terms " epiblast," " mesoblast," and " hypoblast" 

 as indicating the three great groups of cells that are formed in the 

 development of all the higher animals. 



It may be objected to the term " blast " that it would be incon- 

 venient, as the epiblast, hypoblast, and mesoblast contain the 

 " Anlagen " or " blasts " of many organs and structures. But in this 

 hypothetical objection there is contained what seems to me a possible 

 advantage in the recognition of the term " blast " in the sense I 

 suggest. The days are gone by for embryologists to see in the layers 

 of cells known as the epiblast, hypoblast, and mesoblast simple 

 structures of a homogeneous and equivalent nature throughout the 

 animal groups, and there are many who would hesitate before the 

 suggestion of homology between these groups, except in very closely- 

 allied animals. In the case of the mesoblast, it has been recognised 

 almost since the inception of the term that the group of cells is a 

 composite group, containing derivatives fi'om many sources, and 

 containing different sets of derivatives in different animals. For a 

 layer or group of cells that, in the vertebrates, includes a set of 

 primitive structures, " Anlagen " or "blasts" so varied as the primi- 

 tive segments, the- epithelium of the coelom, the sexual cells, the 

 epithelium of the sexual ducts and kidneys, and the beginnings of the 

 connective tissues, blood-vessels, and blood, the term " mesoblasts," 



