112 DR. MARTIN BARRY ON FIBRE. 



ferable to a spiral mode of origin, similar to that producing the fasciculus of filaments 

 in the clot fig. 148 S. And the formation of spirals out of discs in the clot of blood re- 

 sembles in a striking manner that described in the foregoing memoir, as witnessed in 

 the formation of certain tissues: for instance, nerve and muscle. I have just men- 

 tioned the reproduction of filaments by self-division (fig. 148 y, I) as noticed in the 

 clot : a process obviously the same as that described in the memoir as observed in 

 the tissues. But the analogy does not end here. In a former communication-^- 1 

 figured blood-corpuscles (cells) from which the contents, except the nucleus, had been 

 removed by acetic acid. If those figures be referred to, it will be found that the 

 nucleus so remaining is in many instances double. An examination of coagulating 

 blood enables me now to offer some explanation of this curious fact. 



99. In fig. 150 is sketched a blood-corpuscle (cell) presenting a coiled filament, a. 

 This coil having arisen out of the nucleus of the corpuscle or cell, the residual por- 

 tion of the nucleus became double by self-division : and then each half of the nucleus 

 formed a coil, so that an outer coil contained two smaller coils (ft, /3), each having a 

 pellucid centre for future change. We here again find a process in operation, bear- 

 ing a striking resemblance to that producing tissues. Compare with fig. 147. 



100. Where the supply of nutriment goes on, this process of self-division, and the 

 formation of new solid substance, are continued until an entire tissue is produced. 

 Where that supply is soon exhausted, as in coagulating blood, the process in question 

 is speedily at an end. But here also, as in the tissues, greater firmness is acquired as 

 new substance forms. When the supply of nutriment is exhausted, there is no longer 

 a renovation of the nucleus : and now there is seen a cavity (fig. 152 a). This appear- 

 ance is very frequent in the advanced clot. 



101. The best delineations I have met with of coagulated blood, are those by G. 

 GULLIVER;};. They are to be explained, I believe, by the facts above mentioned : as 

 well as those given by the same observer of morbid growths ; which, like healthy 

 tissues, have their origin in corpuscles of the blood||. 



102. In the blood-clot, corpuscles are seen of a much minuter size than those usu- 

 ally circulating in the animal. Such corpuscles are constantly met with in the clot 

 of the Frog and Newt. They owe their origin to previous corpuscles ; a filament is 

 often to be seen within them ; they are frequently membranous at the surface ; more 

 or less spherical in form ; and generally of a deep red colour. 



103. In a former paper, when describing the origin of the various structures of the 

 body in corpuscles of the blood, I mentioned having noticed a reproduction of red 



t Philosophical Transactions, 1841, Part II. p. 201. Plate XVIII. 



| In GERBER'S " Elements of the General and Minute Anatomy of Man and the Mammalia," PI. XXVIII. 



Ibid. Plates XXIX. XXXI. 



II Dr. HODGKIN informs me that in some perfectly recent cancerous matter which contained particles in many 

 respects resembling those of the blood of reptiles, he saw great numbers of them having an unequivocal tail- 

 like process appended to them, which was evidently formed from the material surrounding the nucleus. 



