March 



Dj 



1917] 



NATURE- 



43 



who has attempted to deal with this subject to 

 any extent. Naturally, at that period Moxon 

 treated of typefounding by the hand method 

 of Casting-, but in the large work now 

 under notice the founding of even single letters 

 is shown to be produced by many machines of 

 various kinds. Hand-casting is rarely used 

 nowadays, except^ for the occasional casting of 

 small orders or for sp>ecial purposes. Further, in 

 adopting mechanical means many of the pre- 

 liminary and finishing stages needful in the old 

 hand method are now dispensed with. 



Even as hand-press work is not to be compared 

 with the output of the p>ower-press, so it is with 

 typefounding — thousands of letters are now 

 turned out in the place of a single hundred, and 

 the comparison is even greater when the rotary 

 system of casting is employed. 



As its title implies, the work is confined to 

 the production of typographical surfaces of all 

 kinds, and this covers a very wide range indeed. 

 It includes not only hand-set types and those 

 composed by different machines, but engraved 

 blocks, reproductions by the stereotype and elec- 

 trotype methods, process blocks, and all other 

 surfaces in relief. The details of designing type 

 faces — a most important matter if a good fount 

 is desired — punch cutting, and the making of the 

 matrices and moulds for the final stage of castin?-, 

 are all admirably described, particularly so from 

 both the draughtsman's and the engineer's point 

 of view. Besides very full and concise descrip- 

 tions of the various casting machines in use at 

 the present time, the different systems of type- 

 composing machines from their first conception up 

 to recent date have several chapters devoted to 

 long and technical descriptions. 



In addition to several useful appendices, much 

 other information of a general character is given 

 — most interesting to those practising, or who 

 are students of, the art of printing — which stamps 

 the volume as a valuable work of reference. 



The numerous diagrams have been very care- 

 fully drawn, and the reproductions of other illus- 

 trations are equally well rendered. These, with a 

 number of useful tables, a technical vocabulary in 

 three languages, and a very full index, complete 

 a work which must create a demand for its 

 possession. 



The authors are deserving of praise for the 

 careful labour they have bestowed on the compila- 

 tion of this bulky and useful volume. It certainly 

 must be a great revelation to non-technical readers, 

 who can have but a faint idea of the vast amount 

 of detail underlying the fundamental stage of pre- 

 paring typographical surfaces for the printing 

 press, the greater portion of which only de- 

 veloped during the closing years of the nineteenth 

 centurv. It all helps to prove how necessary a 

 scientific training is for the technical education 

 of our future craftsmen. 



The typographical production of the book itself 

 must have been a great tax on the resources of the 

 printers responsible, and they are to be con- 

 gratulated on the result. 



NO. 2472, VOL. 99] 



IS VARIATION A REALITY? 

 Evolution by Means of Hybridization. By J. P. 

 Lotsy. Pp. viii + 166. (The Hague : Martinus 

 Xijhoflf, 1916.) Price 65. net. 



DR. LOTSY 'S book is one ot many signs that 

 biologists are growing uneasy about the 

 adequacy of evolutionary theory. By whatever 

 doubts the doctrine of Selection was assailed, it 

 has hitherto been common ground that in their 

 generations the forms of life varied abundantly, 

 and that somehow through these variations the 

 diversity of species had come to pass. Modern 

 genetic research has led to the paradoxical dis- 

 covery that much of the best evidence of variability 

 is capable of other interpretations. Consider the 

 " variation" of any polymorphic moth. No one 

 doubted that from any of the varieties any other 

 might be bred. Now we see that was a mistake. 

 Such variation is not promiscuous, and the varie- 

 ties are really an orderly series consisting of dis- 

 tinct types which will breed as true as any species, 

 and of mongrel forms which can throw certain 

 fixed types, and those only. The Mendelian con- 

 ception of the homozygote has raised a new 

 problem. The question arises : Can the offspring 

 of homozygotes vary? Dr. Lotsy is sure they 

 cannot. New forms can only come by crossing. 

 That is the thesis of this book. ''Crossing, 

 therefore, is the cause of the origin of new types; 

 heredity perpetuates them; selection is the cause, 

 not of their origin, as was formerly supposed, but 

 of their extinction." 



This is a bold pronouncement, and it contains 

 much of truth. We think not merely of the many 

 species suspected of hybrid origin, but compre- 

 hensively of the innumerable species, now perfectly 

 distinct, which can quite reasonably be thought of 

 as segregates derived from some cross ages ago. 

 Few also now believe that the domesticated forms 

 comprising many breeds real'v had single origins. 

 Apart from difficulties introduced by exact genetic 

 knowledge, modern writers have felt driven to 

 suggest " polyphyletic " origins for pigeons, 

 fowls, dogs, cereals, the common fruits, 

 etc. Almost whenever the history- of a modern 

 breed is known it can be traced to a cross. 

 Dr. Lotsy took over a wonderful Fo from a cross 

 in Antirrhinum made by Prof. Baur, and, as he 

 rightly says, it contained many types capable of 

 perpetuation as incontrovertible species. Most 

 geneticists have seen such series and been tempted 

 to similar conjectures. But Dr. Lotsy is for 

 taking still wider flights. Geology shows, he says, 

 that new classes appear suddenly with many highly 

 differentiated forms — the Cycads, for instance, of 

 Mesozoic times. May not they be the direct con- 

 sequence of some cross? Perhaps; but whence 

 came the original diversity? Why were there 

 distinct forms ready to be crossed? We find no 

 answer to that fundamental question- In the 

 view of the present writer, too, the doctrine of 

 invariability of the homozygote cannot be main- 

 tained. Variability is rarer than we supposed, 

 but it is a genuine phenomenon witnessed in un- 

 impeachable examples. 



