56 BIOPLASM DESTITUTE OF NUCLEI. 



87. Biopiasm destitute of nuclei. — Bioplasm in a 

 comparatively quiescent state is not unfrequently 

 entii-ely destitute of nuclei, but these bodies some- 

 times make their appearance if the mass be more 

 freely supplied with nutrient matter. This fact may 

 be noticed in the case of the connective tissue cor- 

 puscles, and the masses of bioplasm connected with 

 the Avails of vessels, nerves, muscular tissue, epithe- 

 lium, &c., which often exhibit no nuclei (or according 

 to some, nucleoli) ; but soon after these tissues have 

 been supplied with an increased quantity of pabulum, 

 as I have shown is the case in all fevers and in- 

 flammations, several small nuclei make their ap- 

 pearance in difierent parts of the bioplasm. 



88. Mode Of origin of nuclei. — So far from nuclei 

 being formed first and the other elements of the 

 elementary part afterwards, deposited around them, as 

 used to be taught, they make their appearance in the 

 substance of a pre-existing mass of bioplasm, as has 

 been already stated. The true nucleus and nucleolus 

 are not composed of special constituents differing 

 from the bioplasm in chemical composition, nor do 

 they perform any special operations. Small oil-glo- 

 bules, wliich invariably result from post-mortem 

 change in any form of bioplasm matter, have often 

 been mistaken for nuclei and nucleoli, but these terms 

 if employed at all should be restricted to the new 

 centres of liAang matter referred to. 



89. Production of formed material from bioplasm. 

 — We have now to con rider the manner in which the 

 formed material is produced fi-oni the clear, trans- 

 parent structureless bioplasm, — and this is a most in- 

 teresting inquiry, involving questions of fundamental 

 importance. It has been shown that the amoeba mav 

 become surrounded by a capsule (§ 78), and the 

 outer part of a mucus corpuscle become firmer than 

 bioplasm, so as to form a " cell wall" to the oval mass 

 of living matter. This alteration is probably de- 



