178 



NA TURE 



{July 5, 1877 



1245 this was turned into French metre by the Due de 

 Berry; in 1464 this was turned into French prose, and 

 from this text Caxton took his translation. 



Even abroad the proportion of scientific to other classes 

 of works issued from the early printing presses was com- 

 paratively small ; but this may be satisfactorily enough 

 accounted for by the fact that there were then compara- 

 tively few really scientific works in existence. From the 

 Italian presses a very large number of arithmetical and 

 geometrical works were issued at the end of the fifteenth 

 and beginning of the sixteenth century. The Alphonsine 

 tables were printed at Venice in 1483 ; but one of the 

 earliest works in any way connected with science must 

 have been a folio sheet, " Conjunctiones et opposiciones 

 solis et lunse," dated 1457 ; the place of publication we 

 have been unable to ascertain. There is a " Gerardis 

 Cremonensis Theoria Planetarum," quarto, dated 1472, 

 and an Albertus Magnus " Opus de Animalibus," printed 

 at Rome in 1478. Other early printed works which, con- 

 sidering the time, maybe classed .as scientific, are " Oues- 

 tiones Johannis Cunonici super octo libros Physicorum 

 Aristotelis " (Padua, 1475) ; " Garetani de Thienis in 

 Meteor, libros Aristotelis Expostio " (Padua, 1476) ; 

 " Prognosticon," a meteorological work published at 

 Venice in 1485. But when we come into the next century 

 the number of strictly scientific works published in 

 England and other European countries increased with 

 amazing rapidity, and we may say has gone on increasing 

 in ever enlarging proportion ever since. The first English 

 translation of Euclid by Billingsby is said to have been 

 published in 1570. 



It is a small thing that books of science are all but 

 unrepresented in the Caxton Exhibition ; these could no 

 doubt have been obtained had they been sought for ; but 

 the object of the exhibition is simply to illustrate the 

 origin and growth of the art of printing, which has been 

 an inestimable boon to science as it has been to every 

 other form of human activity, and the man of science 

 owes as much gratitude to its inventors, and to Caxton its 

 ntroducer into England, as does the worker in any 

 other department of culture. Happily, as we hope to 

 show, science has been able to some extent to repay her 

 debt by importing improvements into the art which 

 would not have been possible but for her researches. 



THE DEVELOPMENT OF THE OVUM 

 Biiischli on the Earliest Developmental Processes of the 



Ovum, and on the Conjugation of Infusoria. 

 Studien iiber die ersten Entivicklungsvorgdnoe der 

 Eizelle, die Zelltheilun^ iind die Conjugation dcr Infu- 

 sorien. Von O. Butschli. (Frankfurt, 1876.) 

 TC'EW subjects can be more important in their bearing 



r 



on biology than the more prominent of those con- 



sidered in this volume. It now rests on a morphological 

 basis which will never be shaken, that there has been a 

 procession of the most complex animal forms from simpler 

 and still simpler ones, until we reach eventually the uhi- 

 mate of organised simplicity. There may be difficulties 

 n the way, but they are as nothing to the overwhelming 

 evidence which morphology provides in its support ; 

 doubt, indeed, is no longer jpossible ; and every year 



diminishes the circumscribed area of difficulty. But our 

 knowledge hitherto of the developmental processes which 

 take place in the earlier states of the simplest elementary 

 organisms is wholly incompetent. Much labour has been 

 expended, and doubtless good work has been done ; but 

 as it at present stands, it is conflicting, crude, and essen- 

 tially wanting in coincidence and correlation. The work 

 before us is the result of an attempt on the part of its 

 author to penetrate farther into the matter than his pre- 

 decessors, and by completer knowledge to harmonise or 

 explain away conflicting evidence and doubtful interpre- 

 tation, and if possible to give a sequence to the morpho- 

 logical processes in the simplest ova, and in the least 

 apparently organised of animal forms. 



From the smallness of the space at our disposal all 

 consideration of the second subject discussed in this 

 volume must be passed over. It deals with cell and 

 nucleus fission generally ; but as it is chiefly theoretical, 

 we may the more readily omit it, merely remarking that 

 the author concludes that there is a fundamental har- 

 mony in the method of fission in the cells of both animals 

 and plants ; a conclusion which it may be fair generally 

 to admit ; but in the minute detail, only discoverable 

 by prolonged research, there will be found palpable 

 differences. 



That which gives distinction, and to some extent im- 

 portance to the book, is (i) its minute and practical 

 investigation into the earliest changes effected by deve- 

 lopment in the ova of some of the more lowly organised 

 animal forms ; and (2) the abundance of data which 

 it appears to provide for the support of a new theory 

 of propagation amongst the infusoria, which Butschli 

 propounds and advocates. 



The embryological researches under the first head 

 were conducted principally upon the ova of the Nematoid 

 worms and the Rotifers. To a limited extent the living 

 egg was studied ; but the greater part of the results are 

 derived from investigations of the ova treated with acetic 

 acid. This is greatly to be regretted. The difficulties 

 which present themselves in the minute examination of 

 such ova in the living condition, are doubtless great, 

 indeed complete results could scarcely be obtained from 

 this alone. But undoubtedly the continuous examination 

 of a set of living ova in process of development should be 

 can'ied on simultaneously with every method of treatment 

 which will reveal structure and change in ova of the 

 same form in the dead condition. Only in this way can 

 every possible mutation be traced, and its correlation and 

 sequence be established. 



It is extremely difficult to distinguish even striking dis- 

 coveries in this direction from the manifold claims put 

 forward by the many observers. We must state gener- 

 ally the facts as they at present appear, and seek to 

 indicate the points specially claimed as new by Butschli. 

 It is now well known that the ovum is not suddenly 

 formed, and then stimulated into new activity by fertili- 

 sation. It evidently, in its very lowliest condition, goes 

 through a process of internal growth and development ; 

 after which apparently it perishes unless fecundated. In 

 1864 Balbiani endeavoured to prove that besides the 

 germinal vesicle, there existed one still more important^ 

 which he called the embryogenic cell or vesicle in the 

 ovarian ovum ; and it was held by leading embryo logists 



