76 MORBID GROWTH IN GENERAL. 



remain over, giving colour to the theory that the whole process 

 of endogenous cell-formation is independent of the nucleus, and 

 consists of a spheroidal segmentation of the protoplasm, together 

 with a generatio cequivoca of the nuclei. This question, for the 

 present at least, must remain an open one. 



AVe are possessed of details, which are upon the whole very 

 accurate, concerning the mode in which these endogenous cells 

 are set free. The unsegmented portion of the parent-cell may 

 be dissolved in the surrounding fluid, the included cells becoming 

 eo ijyso free ; or the included cell may slip out of its parent. In 

 the latter event a small quantity of fluid usually gathers round 

 the daughter-cell, thus loosening it from its bed ; it then slips 

 out by aid of its own amoeboid contractihty. After its 

 escape the cavity in the interior of the parent-cell ceases to 

 enlarge. The appearance which is left has been compared by 

 Virchow to a circular hole punched out of the parent-cell (fig. 

 30 6). The old designation of these structures as brood-cavities 

 or brood-capsules (Brutriiume oder Brutraumzellen) may be 

 retained, though Virchow^ in discovering them and giving them 

 a name, started from the mistaken notion that the empty cavities 

 were primarily developed in the parent-cells by a process of 

 vacuolation, the daughter- cells originating in the vacuoles by a 

 generatio cequivoca.^ 



§ (-59. It lies in the very nature of the subject, not only that 

 the histological details of morbid growth admit of a generalised 

 exposition, but that we can also give some prelinunary notions 

 of a general character respecting the coarser features of the 

 process, respecting the forms under which it presents itself 

 to the naked eye. These are mainly dej^endent on the locality 

 of the growth, and especially on whether it be situated in the 

 parenchyma of an organ, or more towards its surface. I am 

 well aware that no distinction of this kind can be strictly and 

 universally applied ; but then we are concerned not so much with 



* Volkmann and Steudener suggest that the hitussusception of one cell 

 by the soft bodj' of another may simulate the aspect of endogenous cell- 

 formation. To a certain extent this is undoubtedly true, particularly 

 in the case of epithelioid cancer-cells ; but I cannot think that the whole 

 doctrine of endogenous cell-formation should be brought in question 

 on account of the jDossible chances of an error of observation — an error 

 too which it is not difficult to guard against. 



