AND DENTINE OF THE TEETH. 129 



from the enamel in the fcetal tooth, subsequently becomes the 

 so-called cuticle of the enamel, as, indeetl, Huxley states." 



Again, at page 130 : " When, however, I tested Huxley's 

 new statements, the matter appeared in quite a new light — 

 the more as I could never succeed in discovering a trace of a 

 nucleus in an enamel prism. Huxley, in fact, asserts 'that 

 the enamel is formed beneath the membrana preformativa, 

 and that the membrana preformativa and cuticle of the enamel 

 are identical. In this point — as I have found by examining 

 the fresh teeth of a new-born cliild and those of a six months' 

 fcetus — he is about right." 



I wish I could give the entire force of M. Lent's exquisite 

 and polite acknowledgment of the truth of a fundamental fact 

 for all further theories of dental development, but here is the 

 original, for those who can appreciate it : " Hiermit hat es 

 seine Richtigkeitr 



In this part of M. Lent's paper a second misstatement 

 occurs, somewhat more gross, if possible, than that which I 

 have already had occasion to notice. 



At page 131 he says : " Of nuclei, such as Huxley describes 

 and figures (in the membrana preformativa), I have seen 

 nothing." 



I have carefully re-examined my own paper, to see if I 

 could find any excuse for a statement so utterly contrary to 

 fact as this ; and, for the sake of MM. Lent and KoUiker, I 

 really almost regret to say I can find none whatever. 



I invariably call the membrana preformativa a structureless 

 membrane. I state that Nasmyth's membrane is " about 

 l-2500th to 1-1 600th inch thick, perfectly clear and trans- 

 parent, and, under a high power, exhibits innumerable little 

 ridges upon its outer surface, which bound spaces sometimes 

 oval and sometimes quadrangular, and about l-5000th of an 

 inch in diameter." And I go on to say that this membrane 

 is nothing but the altered structureless membrana prefor- 

 mativa. I am equally at a loss to discover any figures of 

 these " nuclei ;" though it is possible that in consequence of 

 the reticulation not having been carried evenly all over 

 Nasmyth's membrane in fig. 2, a very careless person mio-ht 

 misunderstand the figure — the text, hoAvever, would at once 

 correct this misapprehension. 



I have neither space nor inclination to follow M. Lent fur- 

 ther ; as what has been said proves abundantly the only point 

 worth discussing at all : viz., that the two main facts asserted 

 in my paper are admitted to be bona fide additions to our know- 

 ledge ; in fact, one might almost fancy M. Kolliker address- 

 ing to M. Lent, Balak's famous reproach to Balaam — " I 



VOL. III. K 



