300 Chromosomes in the Spermatogenesis of Anasa Tristis 
kind of evidence, and in addition to this figure he has given us also 
three or four sketches showing second telophases with the chromosomes 
at each pole massed beyond individual recognition, and at one pole of 
each figure he shows a chromosome sonywhat isolated from its fellows. 
Such an inextricable massing of the chromosomes at the poles is even 
more pronounced in Montgomery’s sketch 161 (Text Fig. 1) and it 
seems to us very hazardous to draw such important conclusions from 
these stages unless all the chromosomes are in evidence. For example, 
our Photo. 11, Plate III, might be offered as evidence that in Anasa 
tristis it is the unequal distribution of chromatin in the first division 
which establishes the dimorphism of the spermatozoa, but in the light 
of Photo. 12 such an interpretation becomes untenable, even if we did 
not have the additional evidence of the large number of photographs 
where the division of all the chromosomes of the first spindle is abso- 
lutely demonstrated. Even in Photo. 11 ten large dyads can be counted 
in the right hand pole of this telophase, only the microchromosomes 
being completely obscured and, as stated above, p. 295, the size of 
the daughter eccentric of Photo. 11 is not a safe guide in determining 
its value. M and n of Text Fig. 2 are reproductions of Wilson’s 
sketches of the second spindle. In each of these figures he shows five of 
the eleven chromosomes. In his later paper (06) he has added to the 
evidence on this point his sketch b of Fig. 2 showing the eccentric at one 
pole, 7. e.. with six of the eleven chromosomes at one pole and five of the 
eleven at the opposite pole, and besides this two more sketches (c and d) 
which he interprets as sister groups of a second spindle—one pole (c) 
showing ten chromosomes and the other pole (d) eleven. Wilson’s 
sketches m and n (Text Fig. 2), Montgomery’s sketch 161 (Text Fig. 
1), and Paulmier’s sketch 35 (Text Fig. 3) bear a sufficient resemblance 
to some of our photographs to admit of comparison. They undoubtedly 
represent the same phenomenon as shown in our Photos. 32 to 42 and 
we believe these photographs should be interpreted in the light of those 
in which we have been able to demonstrate the division of this lagging 
chromosome, 7. e., Photos. 26 to 31 and 44, and in the light of all the 
additional data we have been able to offer in support of our belief that 
normally the eccentric chromosome divides in both spindles." 
In the above detailed description of the eccentric chromosome we have 
followed its development from the earliest prophase of the first sperma- 
°In at least two forms, outside the Hemiptera, a structure identified as an 
accessory chromosome has been shown to divide in both spindles and further, 
is figured as a lagging chromosome. 
