MENDELIAN RATIO AND CHROMOSOMES 495 
of chance. This is the first demonstrable case, so far as I know, 
showing that the maternal and paternal chromosomes do not pass 
collectively to given poles. 
Payne, from his work on Gryllotalpa borealis Burm (’12) where he 
reports a large accessory and an unequal pair, the larger member of 
which always passes to the second spermatocyte which receives 
the accessory, argues that there is no haphazard arrangement, as 
is necessary for the explanation of Mendelian phenomena, that 
the chromosomes brought into the male by the egg pass into the 
female producing spermatozoon. A few lines later, in order to 
explain the transmission of characters from father to daughter, 
he says that a satisfactory explanation is found in the synaptic 
stage, assuming an interchange of the smaller units that make up 
the chromosomes. So, after all, he would not have the material 
(chromatin), which is the essential thing contributed to the male 
by the egg, pass into the female determining spermatozoon. - 
Besides, as I shall point out more fully later, (p. 503) an interchange 
of material during synapsis could only affect the second genera- 
tion and not the immediate offspring, though that is what he is 
attempting to explain. 
Arphia. In early prophases the accessory is in the form of a 
U and well condensed (fig. 19x), and the unequal tetrad is nearly 
as dense as the accessory, the longer dyad having a curve at the 
free end as though it had been drawn over towards the free end of 
the shorter (fig. 19 c). One of the large tetrads is only slightly 
less precocious; a fragment of this chromosome is shown at ), 
figure 19. In late prophases the unequal tetrad has become 
straight and the accessory is but slightly curved (fig. 26). They 
are occasionally found associated end to end—a continuation of 
the growth period relation. 
Twenty-five side views of metaphases and anaphases were 
drawn (figs. 52, 54, 55 and 56). Twelve contain the accessory 
and the larger dyad on the same side of the equatorial plate, and 
thirteen the accessory and smaller dyad in the same relation. 
The complex differs from that of Brachystola, as may be seen 
by a comparison of figures 32, Brachystola, and 35, Arphia; (the 
latter lacks the accessory but contains the remainder of the com- 
