AGASSIZ AND WOODWORTH: VARIATIONS IN EUCOPE. 143 
specimen being otherwise fully developed. In no case was it observed 
that deficiency or absence of ovaries entailed a corresponding deficiency 
or absence of other organs. Reduction or suppression does not occur 
in any other organ than ovaries in A. aurita. 
H. C. Sorby found, among A. aurita collected in Suffolk and Essex, a 
“few per thousand” abnormal specimens exhibiting sixfold, fivefold, 
threefold, and partial twofold symmetry. References to variations in 
Aurelia, Clavatella, Sarsia, and Stomobrachium may be found also 
in Bateson's * Materials for the Study of Variation," pp. 421-429. 
Edward T. Browne examined 383 specimens of A. aurita. He found 
that eight specimens (2.08%) exhibited numerical variations in the geni- 
tal sacs, buccal arms, and tentaculocysts. The number of the genital sacs 
and of the buccal arms varied from three to six. He concludes that 
there appeared to be a correlation between genital sacs and buecal arms, 
but that the tentaculocysts vary independently of these. Eighty-seven 
cases (22.8%) showed variation in the number of tentaculocysts. 
Twenty of these had less, and the remainder more, thau the normal 
number. The range of variation in tentaculocysts was 6 to 15. 
The preceding observations on the variations of Aurelia show some 
striking differences from those we have made on Eucope. While in 
Aurelia there is a general correlation between the number of segments 
of genital sacs, of buccal lobes, and of tentaculocysts, there is no such 
correlation in the variations of Eucope. The sense organs in Eucope 
vary, both in number and in position, irrespectively of the number of 
radial canals and of segments. Neither multiplication nor abortion of 
parts in Eucope is symmetrical. The suppression of genital sacs is quite 
common in Eucope, while it is rare in Aurelia. In Eucope suppression 
is not limited to genital sacs; as in Aurelia, it extends to the otolith- 
bearing tentacles. As far as we have observed, the number of terminal 
folds of the manubrium does not vary in Kucope, and is not correlated 
to the number of segments. 
The apparatus used in making the photographs was the large photo- 
mierographie apparatus of Zeiss, with some modifieations, direet sun- 
light being employed by means of a heliostat of the automatie kind, 
and all exposures were instantaneous, The camera was always used in 
the horizontal position, so that with an objective of low power the full 
length of the bellows could be employed to obtain sufficient, magnilica- 
tion with the least loss of light. The objectives employed in photo- 
graphing Eucope were those of 35 and 70 mm. focus, the lower power 
being employed with the larger specimens. The exposures were made 
