Thomas Ifarrison Montgoineryf 
349 
was the author of several more general contributions on evolution and 
phylogeny, of which the most important was his well known book entitled 
“Analysis of Racial Descent in Anirnals”, publishcd in 1906. 
Montgomery’s favorite studies w'ere however in cytology; and his 
name is perhaps most widely known, at least outside his own country, 
for his work in this field. While extending over a wide ränge, these 
studies always centered in the problems of the chromosomes, to which 
he returned again and again in successive papers. He was an ardent 
advocate of the hypothesis of the individuality of the chromosomes, and 
of the reality of synapsis and the reduction-division, and contribnted 
many important observations in their Support. With him originated 
one of the most fundamental conclusions in this field of inquiry, namely, 
that the conjugation of chromosomes two by two in synapsis (earlier 
suggested by Henking) involves the union of each chromosome of paternal 
descent with a corresponding or homologous one of maternal descent, 
and that (in his words) “In synapsis we see the final process in the con- 
jugation of the germ-cells, namely, the conjugation of the chromosomes”. 
This conclusion, first stated in his work entitled “A Study of the Germ 
Cells of Metazoa” (1901) has become one of the central points of interest 
in recent cytological research. The evidence on which Montgomery 
based this all important result was indirect and therefore inadequate, 
for it was derived almost solely from a comparison of the size-relations 
of the chromosomes in the diploid and haploid nuclei; but much ad- 
ditional evidence in its favor was subsequently brought forward, by 
himself and other observers. Perhaps the strongest and most direct of 
this evidence is given by the history of those modified types of chromo- 
somes to which Montgomery gave the name of “heterochroniosomes” 
(1904) or “allosomes” (1906); and in their investigation he was, after 
Henking, the pioneer, though the discovery of their relation to sex- 
production was made by other observers. With Sutton, he was one of 
the first to urge the constancy and significance of the size-differences 
among the chromosomes, to recognize the fact that the chromosomes of 
the diploid nuclei may in some instances be paü’ed off two by two ac- 
cording to their size, and to advocate the view that the two members 
of each pair are paternal and maternal homologues. He was the first 
to observe that an actual arrangement of the chromosomes in pairs some- 
times exists in the diploid nuclei (1906) — a fact since established in a 
considerable number of cases — and he first maintained that such a 
grouping of the chromosomes is a general characteristic of the diploid 
nuclei (1906). 
Archiv f. Zellforschung. IX. 
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