1914] ELKINS—MATURATION IN SMILAX 45 
toward the poles of the spindle where the nucleolar mass is resolved 
into large chromosomes. Upon decolorization, small portions, the 
size of the prophasic chromosomes, at the equatorial ends of the 
large chromosomes strongly retain the stain. The deeply stained 
portions of the large chromosomes BERGHS considers the ‘“‘chromo- 
somes veritables.”” In describing the larger bodies the word 
“chromosome”’ is used merely for convenience. 
From the observations just noted, we may draw the conclusion 
that there are substances which are not chromatic in the sense of 
being the carriers of hereditary qualities, but which at some stages 
have the same appearance and pass through certain phases in 
closest proximity to the real chromosome. CARRUTHERS (6) sug- 
gests that the extruded bodies are masses of nutritive material 
for which the nucleus has no further use. 
Conditions in Smilax herbacea do not support the theory of 
persistence of the chromosome as a physical unit, but of a smaller 
unit. The number of chromatin bodies in the microspore mother 
cell exceeds the number of somatic chromosomes ; the same is 
true of the somatic nuclei of the nucellus. As these chromatin 
bodies vary in size, we consider that they are aggregates of units 
or chromomeres; also that the size of the chromomere aggregate 
varies with the number of units contained in it. Finally, during 
synapsis the chromomere aggregates form chromosomes according 
to a law of natural affinity. There is no evidence of a loss of chro- 
matin or chromatin-like material. 
PAIRING OF CHROMATIC ELEMENTS.—Closely connected with the 
theory of the persistence of chromatic units is the theory of the 
pairing of parental elements throughout the sporophytic phase. 
Before the theory of permanent, paired chromatic units was 
advanced, “pairing” was described only in connection with the 
prophase of the first meiotic division where parallel conjugation 
(parasynapsis or parasyndesis) of thin chromatic filaments was 
considered typical. A large group of cytologists now present a dif- 
ferent mode of conjugation, namely, of the “end to end” type 
(telosynapsis or metasyndesis). 
__ The difference between the two methods is not as important as 
it seems to be. Too much stress has been laid on the comparative 
