403 
perty of the Yellow Cells to grow and reproduce themselves 
after the death of the organism to which they are supposed 
to belong, and then the remarkable quantity of starch which 
they produce according to the important discovery of Haeckel, 
which I can confirm, are phenomena which, though certainly 
not decisive as the signification of the Yellow Cells yet 
appear very surprising if belonging to the life-history of the 
Radiolaria. 
Odessa, 27th April, 1871. 
Norte.—lodine stains, as Haeckel rightly states (‘ Jenaische Zeitschrift,’ 
1870, p. 534; ‘Quart. Journ. of Micros. Science,’ January, 1871), most of 
the corpuscles enclosed in the yellow cells, blue. In order to obtain the 
reaction clearly, I have first extracted the yellow pigment with alcohol and 
then acted upon the Radiolarian several times with strong iodine tincture. 
With the chloride-of-zinc-iodine solution the coloration comes out more 
quickly and intensely. 
Notes on the Gexus Dotiotum. By Epwarp L. Moss, 
M.D., F.R.C.S.I., Assistant-Surgeon R.N. 
(Read before the Dublin Microscopical Club.) 
THERE can be but little doubt that the distribution of 
ocean surface life is considerably influenced by the great 
systems of oceanic circulation which recent researches have 
disclosed. Such circulation probably tends to assimilate the 
inhabitants of adjacent ocean basins, and helps to explain 
the remarkable similarity in the faunas of even widely sepa- 
rated seas. But unless surface animals can live with equal 
facility at considerable depths, a sort of retentive selection 
will be exerted on those that drift in through narrow straits 
into seas like the Mediterranean, where the surface waters 
have an average inward flow, and where the denser outward 
current is in depths removed from the direct influence of 
light and air. . 
Like other Pelagic Tunicates, the genus Doliolum possesses 
a wide geographical range; but nevertheless, if I can judge 
by the results of my own “fishing” during voyages over 
more than a hundred thousand miles of Atlantic and neigh- 
bouring seas, it is far from being as widely spread as many 
of its relatives. Salpa, Appendicularia, and Pyrosoma, are 
not uncommon in the Mexican Gulf and Caribbean Sea, but 
Doliolum has never been captured in either. I have met 
with isolated specimens off Cape Clear, Cape St. Vincent, 
VOL. XI.—NEW SER. D D 
