1074 ' REPORT—1885. 
‘with a series of hexagonal reticulations like those of the ruminant honeycomb 
stomach. When the edge of the ovum is examined, the septa bounding the reticu- 
lations stand out prominently, and in sections made by Mr. Prince these would 
‘appear to be modifications of the outer surface of the zona radiata. Insome views 
‘the free edges of these reticulations are minutely crenate. The yolk, as in many 
-other pelagic ova, is transparent. 
So far as observed, a considerable number of ova—proportionately to the size 
-of the ovaries—seem to arrive at maturity simultaneously. 
This ground-loving fish has therefore truly pelagic eggs; but, unfortunately, 
‘this season the sexes were not simultaneously procured in a condition to carry out 
the development. 
19. On the Zoocytium or Gelatinous Matrix of Ophrydium versatile. 
By Professor ALLEN Harker, F.L.S. 
Unusual opportunities of obtaining the colonies of Ophrydium versatile in very 
large quantities during the past summer have led to my devoting some time to the 
‘study of the gelatinous matrix, in or upon which the infusorium is found. I have 
got as much as a quart measure full of the colonies in a few minutes in our canal. 
The apparently spheroidal mass is not solid, but forms an irregular hollow spheroid, 
‘and in or upon the outer surface the individual Ophrydia are situated at regular 
distances from each other. The colony is at first found attached to the submerged 
stems of Myriophyllum and Anacharis, at as much as two or three feet below the 
surface, the hollow usually containing a large bubble of gas. After a while the 
‘colony detaches itself and rises to the surface, and floats about for somedays. The 
infusoria then leave the zoocytium, which continues to float about, attracting a 
miscellaneous collection of diatoms and other alge, infusoria, worms, and arthro- 
‘podous larvee, becoming a perfect menagerie of living beings. 
In perfectly fresh slices of the colony, under a power of 300 diameters and up- 
wards, a large number of unbranched threads, regularly divided by septa, are in- 
variably to be found, and on one occasion I found one of these threads in active 
motion, suggesting a filamentous alga allied to oscillatoria. The dried gelatinous 
‘substance has by many botanists been described as a plant, and Suhr described it 
as Coccochloris pila; but Rabenhorst excludes it, and adds, ‘ Specimina omnia que 
vidi in algis meis Europeeis sic et duo in herbario Suhriano pertinent ad Ophry- 
dium versatile’ (animalculum! ). 
Wrzesniowski, in his paper on Ophrydiwm in the ‘ Zeitschrift fiir Wissenschaftl. 
Zoologie,’ 1877, figures and describes the long dichotomously branching thread- 
like pedicle of the animals, and this is recognisable in suitably mounted slices under 
¢ Obj., but, so far as has been observed, the threads I describe do not appear to be 
similar. It is just possible they may be accidental visitors in the colony, though 
they very closely resemble specimens of Aphanothece stagnalis which I have exa- 
mined, this being an Alga with a dense gelatinous exudation. 
The gelatinous mass associated with Ophrydiwm is of a very obstinate character, 
and resists the action of almost any reagents but strong sulphuric acid. 
After boiling in distilled water for half an hour the gelatinous character is 
almost unaltered, and only after prolonged boiling in weak potassium hydroxide 
‘could the solution of the jelly be obtained. After some hours’ boiling, and sub- 
sequent treatment with weak acetic acid to get rid of the carbonate of lime (whole 
minute crystals are distributed throughout the mass), the residue, a flocculent 
mass, is found to consist entirely of the threads before mentioned. These do not 
‘change colour on the addition of strong nitric acid; nor, again, do they give satis- 
factorily the celluloid reaction with iodine and sulphuric acid. Their nature re- 
mains an open question. The author adds some further notes on the animal. 
When light is allowed to fall only on a part of the colony, all the animals in a 
very short time congregate to that part of the zoocytium, and on the whole being 
freely exposed again to light they partially spread themselves over the surface, 
though a majority leave the matrix altogether. In tanks they showed no dis- 
position to form new colonies as described by Savile Kent, but collected in masses 
