506 
L. DONCASTER. 
(17, 18). In the eggs of females of the strain with 55 there 
are 28 in one equatorial plate of the second polar division, 
27 in the otherd Since the females of this strain have 55 
(diploid number),^ and since all spermatozoa almost certainly 
Text-fig, 4. 
• • 
0 
# 
Outer 
Inner 
Two upper chromosome groups, P h r a g m a t o h i a f u 1 i g i n o s a , 
after Seiler : On the left, outer polar plate, 27 ordinary and 
one large chromosome (total 28). On the right, inner polar 
plate, which gives rise to egg nucleus, 27 ordinary and one large 
chromosome divided (total 29 ). Each figure was reconstructed 
from two sections. Two lower chromosome groups. Abraxas 
grossulariata : On the left, outer polar plate, 28 chromo- 
somes ; on the right, inner polar plate with 27, The two groups 
are separated by one section which contains no chromosomes ; 
all the chromosomes of each group are in one section. 
* There are certain points in connection with this case which still 
require further investigation, but that in eggs of this strain one polar 
plate has 27, the other 28, ajDpears to be incontestible. In females not 
belonging to the strain referred to, both polar plates have 28, as would 
be expected from the oogonial number, 56, 
2 The exception in family 12’25, mentioned in the paper referred to, 
will be discussed in the full paper ; no other exception to the number 55 
was found in over forty larvsB of this strain in which oogonial figures 
could be counted. 
