No. 2.] ANURIDA MARITIMA. 2277 
disappeared; the chromosomes have lost their stellate structure 
and are fused into irregular masses. The whole cell appears 
as a mass of deeply stained chromatin. The final stage when 
the egg envelope is fully formed and the nutritive cells have 
entirely disappeared is reached before the egg is laid, no sign 
of any outside cells being present in the last stages of the 
ovarian egg. 
It is clear from the foregoing description that the envelope 
formed is not a chorion in the true sense of the word. It is 
a ‘ Dottermembran,” “ Dotterhaut,” such as is found among 
crustaceans, and is described in many myriapods. Schmidt 
(95) in describing Pauropus designates the egg envelope as a 
‘«‘Dottermembran,” and gives a process of development closely 
similar to that described for Anurida. Among insects the 
outer envelope is without exception, so far as determined, a 
true chorion formed by the follicular cells of the egg tube. 
The vitelline membrane which appears later is, however, a 
true “ Dotterhaut’’ formed by the surface of the egg. This 
rule does not hold with Anurida; here the ovarian membrane 
is formed by the egg itself and is a “ Dotterhaut,” as also is 
the vitelline membrane which is formed after the egg is laid. 
Hence, in this respect Anurida resembles myriapods and crus- 
taceans rather than insects. 
It is hardly necessary to say that the paired structure of the 
ovary is entirely obscured in the mature stages of egg develop- 
ment. Eggs are crowded back into the short unpaired part 
and fill the body down to the oviduct. Ova are crowded above 
and below the alimentary tract, and no available space in the 
body is unused. 
Ovaries after egg laying are irregular and collapsed. The 
only germinal cells present are in the mass of germinal epithe- 
lium. There are no large ova or traces of nutritive cells and 
cell masses. Whether the animals survive and lay again in 
the following summer or whether they die after one season 
has not been determined. The only evidence on the matter is 
this: towards the end of the summer the adult animals become 
scarcer, although eggs are still abundant. In the early spring, 
the beginning of April, there are none to be found anywhere, 
