NOTE. 
TELOSYNAPSIS AND PARASYNAPSIS.— There exists at the present 
time a considerable amount of confusion as to the actual nature of the controversial 
points which cluster, or are supposed to cluster, around the manner of pairing of the 
somatic chromosomes at meiosis, whereby the well-known heterotype chromosomes are 
produced. This confusion is due in great part to the attempts which have been made 
to crystallize the essential differences between two divergent schools of interpretation 
by the introduction of the terms Telosynapsis and Parasynapsis respectively. 
But it must have become evident to every one at all conversant with the current 
work on mitosis, that however appropriate these terms may be to express a special 
mode of chromosome union, they have now become rather misleading to any one not 
familiar with the details of cytological advance within the last few years. The fact is, 
that by emphasizing a point of comparative unimportance, they have led to a mis- 
conception on the part of many people, as to the really fundamental differences which 
still divide the two schools of investigators. 
Montgomery in America, and Farmer and Moore in England, working indepen- 
dently on very different material, came to the conclusion that the heterotype chromo- 
some arose as the result of an end-to-end union — or a lack of disjunction — of a pair 
of somatic chromosomes. These paired chromosomes are arranged more or less in 
the form of an open loop, the sides of which they constitute. The familiar figures 
observed at diakinesis, and at still earlier stages, depend on the various ways in which 
the limbs of a loop behave as they approximate towards, or coil round, each other. 
In formulating this explanation, the investigators above named were mainly 
influenced by the very common occurrence of loop-like figures at an earlier stage, 
which were also traced through succeeding phases ; the turn of the loop was supposed 
to coincide with the point of union between the two somatic chromosomes. 
The closer approximation of the sides of a loop was believed by the English 
authors to take effect at the stage called ‘ second contraction ’, a stage which, where 
it was discerned, appeared to be one of very short duration, and consequently is easily 
missed. It is obvious, however, that there is no essential difference between a lateral 
approximation achieved by the twisting together of the sides of such a loop, and 
an approximation produced by the coming together in pairs of chromosomes hitherto 
disunited, nor is it a matter of any importance whether the approximation occurs 
at a somewhat earlier or later period in mitosis. 
The really vital question at issue between the two schools does not, as a matter 
of fact, consist in Telosynapsis v. Parasynapsis as etymologically understood, but 
upon the interpretation to be placed on the much earlier stages of prophase in the hetero- 
type mitosis. 
Investigators, represented in the first instance by Grdgoire and his pupils, who 
hold the ‘ Parasynaptist 5 view, believe that the early so-called longitudinal fission of the 
chromosomes marks the union of the pairs of somatic chromosomes. Furthermore, 
they attach no importance to second contraction , which is interpreted by their oppo- 
[ Annals of Botany, Vol. XXVI. No. CII. April, 1912.] 
