844 



SCIENCE. 



[N. S. Vol. V. No. 126. 



knows the meaning of 'type' and 'typical,' 

 but the meaning of those terms to the zoologist 

 is something quite diflferent. The scientific 

 man is constantly hampered by the formalities 

 of his science ; and zoology is not advanced by 

 the fact that the holotype, and perhaps the 

 paratypes, of a species are often aberrant forms, 

 i. e., are not typical in the ordinary English 

 sense. Of this no instances need be quoted. 



Now while many individuals of a species 

 may be typical (in the ordinary sense), we can 

 conceive of one form, not necessarily existing, 

 that represents a kind of central type, or, as I 

 have expressed it elsewhere, a composite por- 

 trait of the species. It is this that is the ' type ' 

 of the man in the street. Instances of this are 

 to be found in the statistical tables of Galton, 

 Weldon, Bateson and others ; a type-formula 

 for Ranunculus repens was given by Pledge in 

 Natural Science for May, 1897 ; but some of 

 the most interesting are J. M. Clarke's studies 

 of Leptodesma {Amer Geol., April, 1894, and 

 Nat. Sci., June, 1894). 



For this kind of type, far removed from a 

 type-specimen, we want a name ; and as the 

 word type has been stolen from us it will save 

 confusion to avoid it altogether. J. M. Clarke 

 used ' fundamentum ' as an alternative ; but 

 other American biologists attempted to use this 

 as the equivalent of Anlage, while the funda- 

 ment of man in the street is quite a different 

 anatomical conception. Perhaps the word 

 'norm,' with its adjectival form 'normal,' 

 would give the meaning most nearly, though 

 ' normal has, of course, its more literal sense of 

 'at right angles to.' The norm of a species 

 varies with locality or with horizon, becoming 

 in the former case the norm of a subspecies, in 

 the latter case the norm of a mutation. So 

 also one can sometimes imagine the norm of a 

 genus ; and how very diiferent a thing that 

 would be from the type-species, at least of many 

 genera ! The genus norm also may vary with 

 locality. Thus the species of G-issocrinus in 

 Gotland group themselves around G. typus, but 

 those in England around G. goniodactylus. 



This conception of the norm will probably be 

 found at least as helpful as that of the ' hypo- 

 plastotype. ' It would be of value if it did no 

 more than draw our thoughts from the weari- 



some history of human error back to the facts 

 of nature. 



With reference to what Mr. Schuchert calls a 

 'plastotype,' but which I would as lief call a 

 'cast o'type,' or perhaps 'electr-o-type,' may 

 I put to him the case of a cast made from a na- 

 tural matrix which has subsequently been partly 

 destroyed, in order to expose its inner recesses 

 more fully or to admit of the extraction of the 

 cast ? Such a cast would preserve features that 

 could never again be shown by the matrix, and 

 might therefore find a place in the hierarchy 

 labelled ' type material ' by Mr. Schuchert. 



Another question. When the holotype and 

 paratypes of a species have gone the way of all 

 flesh ; when topotypes are impossible and meta- 

 types unknown ; when even its plastotypes are 

 not to be had — then what are we to call the 

 specimen selected for special description by the 

 reviser and reestablisher of the species ? Should 

 it not be something distinct from the ordinary 

 'hypotype?' But this subject of hypotypes 

 offers so wide a field for the neologist that pru- 

 dence bids me cease. F. A. Bathee. 



British Museum (Natural History). 



' organic selection. ' 



To THE Editor of Science : In Science for 

 April 23, 1897, J. Mark Baldwin submitted, in 

 a paper headed ' Organic Selection,' an hypoth- 

 esis which he implies to have originated ' in 

 certain recent publications ' by H. F. Osborn, C. 

 Lloyd Morgan and himself in the year 1896. The 

 hypothesis is based on the idea that characters 

 acquired during the life of an individual are, to 

 a considerable extent, those characters which 

 cause the survival of that individual ; or, in other 

 words, that an organism which varies not only 

 because of variations in the germ-cell, whence it 

 evolves, but also because of the variety of forces 

 acting on it while it is so evolving (especially 

 afterbirth), and, on account of these variations, 

 survives and reproduces at the expense of other 

 organisms, must so survive partly on account of 

 the one set of variations and partly on account of 

 the other set. On this basis it is argued that, 

 as connate characters in general persist, those 

 particular connate characters which are identical 

 with those acquired characters with which they 

 coexist and to the virtue of which the survival of 



