r2 MORBID GROWTH IN GENERAL. 



of the nucleuSj is an increase in the amount of protoplasm. 

 Apart from the a priori difficulty of conceiving how, without a 

 proportionate increase in the bulk of the individual cell, it can 

 i'Lirnish an amount of matter nearly twice as great as itself, wc 

 ha\ e the direct evidence of the microscope ; this increase in 

 volume having been observed so often that its occurrence is no 

 longer open to any doubt. 



Fission of the nucleus, together with increase in the amount 

 of protoplasm, thus make up the first stage in the genesis of cells. 

 The process may be arrested at this point ; it may be limited to 

 a repeated multiplication of nuclei with increase in the amount 

 of protoplasm. It then gives rise to those peculiar structures 

 which have been described by Robin under the name of myelo- 

 plaques^ or cellules a noyaux multiples. These are comparatively 

 large, single-contoured flakes of a very finely granular, feebly 

 refracting material ; each flake exhibiting in its interior a large 

 number (as many as twenty to thirty) of round nuclei, furnished 

 with nucleoli. These structures vary greatly in their external 

 form, which is obviously quite independent of any law of symmetry, 

 being determined by the shape of the cavity which they contri- 

 bute to till. It is only when these giant-cells (VircJioiu) are 

 found embedded in some very soft and yielding tissue that they 

 assume more or less of a globular, or, at all events, rounded 

 shape (fig. 27 a) ; in tissues with a fibrous structure, the giant- 

 cells are furnished with processes, which must be regarded as 

 prolongations of the plasmatic effusion to which the increase in 

 size of the cells is due, into the interfibrillar interstices. This 

 relation is most instructively elucidated by a case of Billrotlis, 

 where the giant-cells originated, in the manner just described, 

 from the cellular elements of muscular fibre. At the periphery 

 of the tumour (which was caused, at least in part, by this very 

 phenomenon) Billroth succeeded in demonstrating that the mus- 

 cular fibres were swollen, and their fibrillas dissociated from one 

 another. The individual giant- cells exhibited the forms figured 

 in fig. 27 h. 1 made a similar observation in the case of a 

 connective-tissue growth in the white substance of the brain. 

 The great point to be borne in mind is, that every giant-cell has 

 really sprung from a pre-existing cellular element ; an example 

 of the almost unbounded formative power at the disposal of the 

 organism in the person of each of its constituent cells. 



