DENDROSOMA RADIANS, EHRENBERG. 
1G7 
Dumber of rows being difficult to determine unless the gem- 
mula is seen sideways and the cilia are moving slowly). Tlie 
number of contractile vacuoles may in some cases be two or 
tour, but is usually three. 
A remarkable point in the structure of these gemmulse is 
that at present we have no definite evidence of the presence 
of micronuclei. Neither in the free-swimming’ gemmul® 
themselves nor in the preparations (both whole mounts or 
sections) of the gemmulaj in the brood-chambers, nor in the 
body of the Lernteophry as and Trichophryas have we 
been able to find the micronuclei in any form. 
Certain deeply stained granules are sometimes found 
scattered in the protoplasm, and some of these may be, and 
probably are, micronuclei. It is very improbable that these 
or any other Aciuetaria are not heterokaryote, but we imagine 
that in Leriunophrya, and possibly in Trichophry a too, 
the micronuclei are very small or involved with the mega- 
nuclei. 
Further investigation is needful before the mystery of the 
micronuclei of these forms is solved. 
Develoi'jient of the Gemjiula. 
We have observed the development of the gemmula in the 
Birmingham material twice. The history of one of these, 
September loth, 1908, was as follows: 
A free-swimming gemmula settled down on the cover-glass 
between 11.45 and 12 noon. The cilia disappeared entirely 
in forty minutes, and as they disappeared short suckers 
were developed all over the body, except, of course, the part 
attached to the cover-slip. As to the method of disappearance 
of the cilia we have nothing but the negative evidence to offer 
that we have not seen them break off. The probability is that 
they are withdrawn. We feel certain that they are not con- 
verted into suckers. At 12.30 the embryo was in a similar 
stage to that represented by fig. 3, and closely resembles the 
stage figured by Biitschli for Trichophrya (2, PI. 78, 6 c.). 
