62 Proceedings of the Royal Physical Society. 
V.—Note on Trypanophis grobbeni, a Protozoan Parasite of 
Siphonophora. By J. F. M. Floyd, M.A., University of Glasgow. 
(With Plate.) 
(Read 27th March 1916. MS. received 27th March 1916.) 
THE material for the following notes was collected during the summer of 
1912, whilst the writer occupied the Oxford Table at the Zoological Station, 
Naples. 
In June the colonies of the siphonophore Halistemma tergestinum were 
richly infected with Zvrypanophis, which, as Keysselitz records,! are found 
throughout the gastro-vascular system of the infected colony —the 
active parasites can easily be seen in situ with the aid of a dissecting 
lens (x 20). 
Examination of the contents of the ccelentera of Velella gave negative 
results. 
Film preparations of 7rypanophis cannot readily be made because of the 
difficulty of ensuring that the animals adhere to the glass. Pieces of the 
Siphonophore were squeezed on to coverslips previously smeared with egg- 
albumen and these allowed almost to dry; by this means a certain number 
could be retained, but a large proportion were always washed off during 
fixation. 
The smears were fixed in strong Flemming’s Solution, bleached with 
hydrogen peroxide and stained in Mayer’s hemalum followed by a trace 
of eosin, or else in iron-hematoxylin. The process of partial drying 
causes the Z'rypanophis to appear broader and more flattened than 
is natural, and in their struggles individuals are liable to assume rather 
distorted shapes—but in life, although extremely active, they undergo 
little or no change of form, differing altogether in this respect from 
Trypanoplasma. 
None of my preparations shows a differentiation within the nucleus 
(“trophonucleus”) of a karyosome, like that figured by Keysselitz. In 
some there is a large clear space like a vacuole, and the nuclear substance 
is more deeply stained round its edges—possibly an artefact. A more finely 
alveolar structure than that of the surrounding cytoplasm is all that can be 
defined. 
1 Arch, f. Protostenk., 111., 1904 
