310 T. H. Morgan 
being present—we can see how the first division should be abor- 
tive if we admit that at this division in many forms the separation 
of the paired chromosomes occurs. ‘To Meves' this interpretation 
would be meaningless since he does not accept the current view 
regarding the nature of the reduced chromosomes, but to those 
who think the evidence at hand points to such an interpretation of 
the reduction division, the assumption here admitted may make 
an appeal. The interpretation would mean that while the ordi- 
nary process of division is attempted it becomes abortive owing to 
the absence of the ordinary chromosomal behavior. Whether 
the result may not also have a real significance so far as the cyto- 
plasm is concerned must be left an open question. 
What meaning then would the second divison have? If the 
first had been, as assumed, the reduction division, the second 
would be an equational were all the chromosomes present. If, 
owing to the failure to separate the sex chromosomes in the first 
the process should take place in the second division, there might 
theoretically be produced two kinds of sperm, “ male- and female- 
producing.” Ifthe former degenerates, all that become functional 
would produce females. Objections to this argument are evident. ° 
The fact that in Vespa both products of the second division become 
functional sperm is fatal to such a view—provided, as seems more 
than probable, the fertilized eggs of Vespa also all produce females. 
The difficulties are not lessened by reversing the first assumption 
regarding the nature of the first spermatocyte division in the bee 
and wasp. In some groups of insects the first and in others the 
second division is supposed to be the reduction division. Nowif 
we assume for the bee that the second is the reduction division 
Wwe may appear to account for the production of a functional 
“female-producing sperm’ (the “male-producing’”’ being the 
rudimentary one); and if we assume for the wasp that the first 
division is the reducing one that separates male from female- 
producing cells—the latter alone dividing in the second—we 
might appear to account for the facts. _[n reality such an interpre- 
tation meets with more difficulties than it explains; it leaves unac- 
14 There is no evidence from Meves’ observations that an accessory passes out in the first spermatocyte 
division. 
