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On some Cases of Hermaphroditism in the Limpet (Patella), 
with Observations regarding the Influence of Nutrition on Sex 
in the Limpet. 
By J. F. Gemuitt, Assistant to Professor of Anatomy, Glasgow University. 
The common limpet (Patella vulgata) may be found anywhere 
on our coasts, adherent to stones, rocks etc., at levels varying from 
a short distance under high water mark downwards. The following 
facts about it require special reference here, as they have a bearing 
on what follows in this paper. 
The sexes are separate and the sexual apparatus is of the sim- 
plest possible type. The genital gland, ovary or testis, is single, and 
its products when ripe pass into one of the kidneys, and reach the 
outside water by means of the kidney duct. (See Ray LANKESTER in 
Encyclopaed. Britannic.) 
No special genital ducts, no copulatory apparatus, and in fact no 
secondary sexual structures at all appear to exist. Ovary and testis 
are equal in bulk, the larger size of the ova being made up for by the 
vastly greater number of spermatozoa. 
As to its habits, many interesting details have been observed by 
Dr. Ropertson of Millport. When uncovered by the tide it remains 
motionless and more or less firmly attached, but when the tide is in, 
it makes short excursions in search of food, never leaving its rock or 
stone, but creeping along the surface by means of its disc-like foot, and 
returning always to its previous position before the tide has left. The 
same limpet may be found on the same spot for an indefinite time, 
and thus its tidal level and nutritional surroundings remain constant. 
I had occasion lately, while working at Millport Marine Station 
to examine carefully a large number of limpets, and among them I 
found several in which the gland was not purely ovarian or testicular, 
but of mixed character. In these cases the genital glands were normal 
in size, shape and position, but their colour was mottled, showing all 
shades between the olive-green of ovary and the light yellow of testis. 
And under the microscope their contents shewed not only ripe ova 
and spermatozoa but also segmented ova and even ciliated freely 
moving embryos. 
Part of the gland in the first case observed, was preserved for 
further microscopic examination and part of it was shed into a vessel 
of filtered sea water. In a short time there were found in the vessel 
