216 Dr Martin Barry on the 



add is, that the origin of new filaments in these nuclei 

 appears to me to have especial reference to that assimilation 

 of which they seem to be the centres. Although every 

 nucleus seems to possess a reproductive property, there are 

 thus special centres of reproduction. Such centres were also 

 particularly indicated in one of my former memoirs,* as ex- 

 isting in the epithelium, the pigmentum nigrum, ' cellular' 

 tissue, and cartilage. In describing tlie first origin of muscle, 

 nerve, and the crystalline lens, also, I directed attention to 

 such centres, stating that we might hereafter see reason for 

 thinking it not unimportant that the contents of the ' primi- 

 tive' cell, and those of the 'secondary' cylinder, should have 

 their origin in the nucleus ; and I was particularly desirous 

 of connecting this fact with the existence of the orifice in 

 question. It will now be seen that I had in view the subject 

 of assimilation now referred to." f 



Such, then, having been my views long since, I can have 

 no hesitation in admitting all the attractive force attributed 

 to those centres by Professor Goodsir ; whose theory of nutri- 

 tion, indeed, harmonizes so fully therewith, that a friend 

 pointed it out to me as the formal application of my views. 

 And on a perusal of the important volume just referred to, 

 by the brothers Goodsir, I have the satisfaction to find, that 

 all in it relating to the " function of the nucleus in cellular 

 development," appears to be derived from the same source. 



I have here great pleasure in acknowledging that Professor 

 Goodsir's discovery of the real structure of basement mem- 

 brane, appears to me an important step towards a solution of 

 the question — How do the corpuscles of the blood enter into 

 the formation of structures arising on the " free surfaces of 

 parts or organs" % That the blood-corpuscles do enter into 

 the formation of such structures, I must take to myself the 

 credit of having shewn, by tracing them into the incipient 

 chorion in the Fallopian tube. J But it is now possible, I 

 think, to offer an explanation of the mode in which they are 



* Phil. Trans., 1841, par. 119, 120, 135, 144. 



t Kdinburgh New Philosophical Journal, October 1, 1843, pp. 207, 208. 



X On the Corpuscles of the Blood, Phil. Trans. 1840. 



