Mr. O. Thomas on a new Semnopitliecus. 475 



are the sole vehicles of herediiy, he would probably be received, 

 and justly, with general derision. I, however, maintain that 

 if, for tiie present, anyone continues to assert that the nucleus 

 is the sole vehicle of heredity, his hypothesis is of no greater 

 value than that just mentioned. 



The above conclusions and remarks will perhaps appear to 

 unprejudiced investigators to be somewhat self-evident. 

 That they were nevertheless not entirely superfluous is proved 

 to me by a new paper by Weismann *^ which actually 

 appeared during the preparation of this little essay. For, in 

 spite of cognizance of Fol's investigations, this author stands 

 fast by his old opinions, and indeed is rather inclined to 

 regard the former as a confirmation of his views. He would 

 most of all prefer to consider the centrosomata as parts belong- 

 ing to the nucleus ; but here he will scarcely meet with the 

 approval of specialists. And as for his other proposition, 

 that the activity of the centrosomata is to be regarded as 

 determined and guided by the nucleus, it is wholly artificial 

 and arbitrary ; indeed it has been demonstrated above that 

 there is not the slightest foundation for such a supposition. 

 We are fully entitled to ask. Why is not the position reversed? 

 Why is not the activity of the nucleus equally well to be 

 regarded as dependent upon that of the centrosoma ? 



In the present state of the case it would be much better to 

 say, the theory that the nucleus alone is the seat of the pro- 

 cesses of heredity was premature, and provisionally we know 

 nothing about it. But if we wish to express conjectures, it 

 is much more probable that the processes of heredity, as well 

 as most of the other vital processes in the cell, depend upon 

 intimate relations between nucleus and plasma (or, to be pre- 

 cise, the directing portion of the plasma — the centrosoma), and 

 that in this respect we have no reason to favour one of these 

 parts more than the other. 



Copenhagen, NoA^ember 1891. 



LIX. — Descri2)tion of a remarkable new Semnopitliecus from 

 JSarawak. By Oldfield ThOMAS. 



Mr. Charles Hose has kindly submitted for my examination 

 the flat skin of a monkey obtained by him some years ago on 

 the coast of North-eastern Sarawak, and this proves to repre- 

 sent a species not merely new, but entirely difterent in its colora- 

 tion from anything jn-eviously described. Among the many 



* A. Weismann, ' Ainjjhiniixis ncler die Vermischung der Individiien, 

 .Tena, 1801. 



