148 



SCIENCE. 



[N. S. Vol. XI. No. 265 



frog's spinal cord," but it is set at rest when 

 we learn from the original that they were ap- 

 plied on the ventral surface of the spinal cord 

 in the immediate neighborhood of a fresh cross- 

 section. Again, some astonishment is caused by 

 finding (on p. 51) that " one important fact that 

 has hitherto been overlooked is the marked varia" 

 tion in calibre of medullated nerve-fibers. ' ' We 

 ask ourselves whether it is possible that Bieder- 

 mann did not know of the long series of investi- 

 gations on this subject, beginning with those of 

 Bidder and Volkmann half a century ago, and 

 continued in our own day by Gaskell and his 

 pupils and numerous other workers ? On turn- 

 ing to the original, however, we find that Bieder- 

 mann's innocent statement is that this important 

 fact has not yet been ' mentioned ' (erwahnt) in 

 his description. Similarly the at first sight 

 somewhat mystifying contention of Griitzner 

 and Tigerstedt (p. 311) " that certain forms, per- 

 haps, indeed, all opening twitches, produced by 

 negative polarization currents are really closing 

 twitches," becomes perfectly rational as a con- 

 tention " dass gewisse Formen, ja vielleicht alle 

 Oeffnungszuckungen durch den negativen Polar, 

 izationsstrom verursachte Schliessungszuckun- 

 gen sind," which, being interpreted, means 

 "that certain forms, indeed perhaps all opening 

 twitches, are closing twitches produced by the 

 negative polarization currents." 



G. N. I. S. 



Text-book of the Embryology of the Invertebrates. 

 By Dr. E. Korschelt and Dr. K. Heidkr_ 

 Translated from the German by Matilda 

 Bernard, revised and edited with additional 

 notes by Martin F. Woodward. Vols. II. 

 and III. London, Swan, Sonnenscheiu & 

 Co.; New York, The Macmillau Co. 1899. 

 The admirable text-book of Invertebrate Em- 

 bryology by Drs. Korschelt and Heider is 

 scarcely in need of recommendation at this late 

 day. If embryologists owe a debt of gratitude 

 to Professor Mark and Dr. Woodworth for the 

 translation of the first volume of the work, 

 their obligations are even greater to those who 

 have undertaken the more arduous task of 

 translating the three remaining volumes. The 

 two volumes just published contain the devel- 

 opment of the Phoronidea, Bryoza, Brachiopoda, 



Crustacea and Insecta. Those volumes have 

 been made of equal size by an adroit transposi- 

 tion of some of the chapters of the original text. 

 One notes with pleasure the abolition of the oft 

 recurring word ' fundamental ' which the trans- 

 lators of the first volume used in the place of 

 the German word ' Anlage. ' As some embry- 

 ologists have of late been much distressed about 

 the proper translation of this term, it may be 

 well to repeat Mr. Woodward's eminently sen- 

 sible remarks on the subject. He says : "Ex- 

 ception, with which I concur, has already been 

 taken to the use of this term [fundament], 

 on the ground that the word fundament im- 

 plies the solid basis or foundation upon which a 

 structure rests or is built, where as an 'Anlage' 

 is essentially a changing, growing, structure, 

 which, though at one time the foundation, 

 when only the foundation exists, eventually 

 gives rise to, or rather itself becomes trans- 

 formed into, the fully formed organ. 



"Having thus decided against the continued 

 use of this term, I found myself face to face 

 with the responsibility of selecting one of the 

 numerous terms which have at one time and 

 another been put forward as the English equiv- 

 alent of ' Anlage,' at the same time time know- 

 ing full well that, whichever word was adopted, 

 I should find a large number of biologists 

 against me, as nearly every teacher of note has 

 proposed at least one word which he believes to 

 be the only correct rendering of ' Anlage.' 



"Kealizing, then, the impossibility of satisfy- 

 ing everyone, I thought it advisable to pass over 

 all the numerous terms which have been re- 

 cently suggested, none of which are really sat- 

 isfactory, and to revert to that much abused 

 word — rudiment. Most biologists will agree 

 that the term rudiment, if it had not been mis- 

 used by some of our most eminent zoologists, 

 would undoubtedly be the best word by which 

 we could render the German term ' Anlage. ' 

 Unfortvinately, following the lead of Darwin 

 and others, we have acquired the habit of ap- 

 plying the terms rudiment and rudimentary to 

 certain structures present in the adult, which, 

 in consequence of their small size and frequent 

 loss of function, have retained a somewhat em- 

 bryonic stamp, thus preserving the outward ap- 

 pearance of a rudiment, but losing its essential 



