130 Proceedings of the Royal Physical Socvety. 
and why Fungi, which live on organic material, z.e., on already 
elaborated matter, have so great an affinity for the red or 
acid dyes. 
To the endonucleolus with its fibres, and to the attractive 
sphere with its corpuscle, I had attributed trophic functions 
in my last paper, but M. Heidenhain’s! researches have 
since shown that the centrosome may be looked upon 
as a centre for locomotion, as in the white blood-corpuscles 
of the Salamander delicate threads, which are apparently 
contractile fibrils, can be traced from the corpuscle to the 
very periphery of the cell. We know further, since v. 
Beneden’s and Neyt’s researches, that during division of 
the cell—when the fibres proceeding from the corpuscle are 
most readily seen—these corpuscles are the active agents 
bringing about a separation of the chromatin segments, which 
have previously undergone either a longitudinal or a trans- 
verse division. 
To the endonucleolus I can also no longer attribute trophic 
functions, as I now believe it to be not a centre comparable 
to the nervous system of higher organisms, but rather a 
space from which channels pass in various directions, these 
channels serving for the distribution of elaborated and easily 
assimilable materials. 
Of the various organs of the cell, none are better known 
than the chlorophyll granules or chloroplasts. We know 
that they are concerned in the production of starch, that 
light is essential for this process, as is also, in all probability, 
iron, ete.; but I cannot now enter more fully into a descrip- 
tion of the various cell organs. What I have stated will be 
sufficient to show that a cell is a highly organised individual, 
and not a bag containing an “emulsion” of protoplasm, .as 
some still fondly believe, who, ignorant of histological 
methods, explain all microscopic appearances as artefacts, 
and who taunt the histologist by exclaiming: You can’t “ fix” 
protoplasm ! 
The working of the cellular machine I cannot illustrate 
better than by referring to the views of Max Verworn, 
'y, Kollicker’s Festschrift, Wiirzburg, 1892. 
2 Max Verworn, Arch. f. Physiol.,. vol. 51, pp. 1-118. 
