494 



In the course of ages one, or more, of the former identical twins, 

 triplets, etc. has become rudimentary or abortive, but it, or they, may 

 reappear in the form of embryomata, finally of tumours, even of 

 carcinoma. In this way it comes to be recognised, that there must 

 be a vast difference among the various vagrant and aberrant germ- 

 cells in potentialities for mischief. Some few, and not all — how many 

 in each case it is at the moment impossible to say, and it may never 

 be determined — possess the potentiality of developing like the embryo 

 containing them. If they do this normally, identical twins, triplets, 

 etc., may result. If they do not degenerate, which is probably often 

 their fate, they may come to lie somewhere or other in the embryo, 

 even in its sexual organs. Here they may be encapsuled for a longer 

 or shorter time, and, finally, one or more of them may commence 

 (abnormal) development, and form an embryoma, a sarcoma, or other 

 tumour, even, by attempting to begin the whole cycle anew with arrest 

 in the embryonic formation, a cancer. Vagrant germ-cells are in 

 development, I imagine, far too numerous for anything like all to be 

 required to account for the tumours, and for cancer. Probably it 

 may be regarded as sufficient, if there be in every development at 

 least 1, 3, or 7 such, which, if they do not degenerate, may become 

 the seed of later tumours. 



To the embryologist it is of great interest to establish, that, as 

 in the upward direction the embryomata pass step by step into 

 identical twins, triplets, etc., so as gradually in the downward one 

 they merge in the simple tumours, and that any portion of the life- 

 cycle of normal development may manifest itself as a tumour. 



Nachdruck verboten. 



On a Case of Numerical deduction of the Carpus. 



By Gr. Elliot Smith, Cairo. 



With 2 Figures. 



In the body of a male Soudanese negro (aet. 35 ann.) I have 



found only seven bones in each carpus, the semilunar (os lunatum) 



being completely fused to the cuneiform (os triquetrum) in both cases. 



of one in a frog. Apart from the morphological distinction between 

 carcinoma and sarcoma, there is probably a great physiological difference 

 in their modes of nutrition. In making these distinctions I would quite 

 admit, that ultimately there might not be much real difference between 

 them. 



