of Chloroplasts aud Leucoplasts, 111 
chondriosomes are organs of the cell, of the same rank as the nucleus, it 
follows that these bodies must be transmitted from individual to individual 
in the form of their primordia and that the chromatin is not the sole carrier 
of the hereditary characteristics. In my own opinion such a view does not 
impair one’s faith in the doctrine that the nucleus is the chief vehicle of 
hereditary characteristics, but it does not give the nucleus the monopoly in 
heredity. There is no sufficiently convincing evidence that the primordia 
of the plastids and the chondriosomes are carried within the cavity of the 
nucleus. They must occur in the cytoplasm of both gametes in all plants. 
Even in such plants as Bryophytes and Pteridophytes there is always 
enough cytoplasm in the sperm to contain these primordia; so there is no 
likelihood of their being omitted from any gamete. 
The very important question now presents itself: What characteristics 
are transmitted solely by the nucleus, and what by the primordia of plastids 
and by chondriosomes? How do these respective characteristics behave in 
heredity ? It is probably admitted on all sides that such characters as are 
known as Mendelian are carried by the chromatin, but chromatin does not 
carry chloroplasts, leucoplasts, or chondriosomes. There are many trans¬ 
missible characteristics that cannot as yet be definitely expressed in any 
Mendelian ratio. To claim that certain phenomena of fluctuating varia¬ 
bility and other numerous characteristics, Mendelian or otherwise, owe their 
appearance and transmission to the primordia of plastids and chondriosomes 
may be a daring hypothesis, but, if, as there is good ground to believe, these 
bodies are permanent organs, there is no escape from some such assumption. 
If, as some have attempted to show, the pigments grouped under the term 
anthocyanin are due to a definite granular or rod-shaped body, which is 
a permanent organ of the cell, are we to conclude that colours, whether 
behaving in the Mendelian ratio or not, are transmitted by the nucleus? 
Naturally we are not to think of nucleus, plastids, and chondriosomes as 
bodies working wholly independently of each other and of the remainder 
of the living substance, which we call the groundwork of cytoplasm. 
A nucleus is not known to operate outside of the cytoplasm, nor can these 
other bodies have any functional existence outside of the cytoplasm. It 
is, of course, idle to speculate, but nothing is clearer to the biologist to-day 
than that the living substance has a much greater complexity than was 
formerly attributed to it. There was a time not very remote when cyto- 
logists were somewhat content to believe that dilute solutions of certain 
acid or alkaline combinations were sufficient to reveal every part of the 
cell contents visible to high powers of the microscope. At present it is 
known that while certain parts of the cell are beautifully revealed by the 
use of certain reagents, other parts are destroyed or rendered unrecognizable 
by these reagents. Varied and complex phenomena have their basis in 
varied and complex morphological entities. 
