THE CELL DOCTRINE. 97 



believed by Dr. Beale to take place to a greater or 

 less extent, the little masses of germinal matter or 

 nuclei in the capillary walls also taking part, often 

 increasing in size to such degree that they materi- 

 ally obstruct the passage of the blood, and by drop- 

 ping oft" portions give rise to bodies floating in the 

 blood precisely similar to white blood-corpuscles, or 

 pus-corpuscles ; indeed, Dr. Beale considers that this 

 may be one of the sources of origin of the white 

 blood-corpuscle.* 



So, also, tubercle is believed by Dr. Beale to result 

 either from the multiplication of masses of germinal 

 matter which have passed through the capillary 

 walls from the blood, or from the masses of germinal 

 matter usually termed nuclei, in connection with 

 the capillary walls. He says, in illustration : " In a 

 case of tubercle, which was very rapidly developed 

 upon the surface of the pia mater, in a man of tuber- 

 cular constitution,. I proved most distinctly that the 

 tubercles were connected with the vascular walls, 

 and that if the nuclei had not given origin to them, 

 they were certainly implicated. My own opinion is, 

 that these nuclei gave origin to the tubercle-cor- 

 puscles, in consequence of receiving from the blood 

 peculiar nutrient matter. In the lung I have seen 

 appearances which point to a similar conclusion."t 

 Would not these views arise from appearances pre- 



* Beale, Microscope in Clinical Medicine, third ed. London, 

 1867, p. 166. 

 f Microscope in Clinical Medicine, third ed., 1867, p. 205. 



9 



