546 
JOTTINGS FROM THE BIOLOGICAL LABORATORY. 
surface (fig. 2) has the appearance of a minute honeycomb, owing 
to its being covered over with numerous rows of minute apertures, 
arranged with the greatest regularity. 
On the free flap of the 3rd tentacle covering over the 1st, there 
is to be observed an oval dark patch, which to the naked eye 
appears minutely tuberculated. When this is examined under a 
lens (fig. 3) the tubercles are found to be minute elevations, each 
with a rounded aperture at its summit. Microscopic sections shew 
the thickened patch to contain numerous branching glands, the 
ducts of which open at the apertures mentioned. The specimens 
were not in good order for histological study; but the cells of the 
glands were found to be full of large rounded granules. 
The remaining portion of the inner series (internal labial 
tentacles of Owen,* labial tentacular lobe of Kefersteinf) 
is fully developed only in the female. It consists of a 
large flattened median lobe, situated posteriorly in immediate 
contact with the buccal mass. It is divided by a deep 
median notch into two parts, each of which bears fourteen 
tentacles. On the middle of its inner surface is an oval patch 
where the integument is raised up into numerous closely set 
ridges, which are in series with the tentacles, the most external 
ridges and the most internal tentacles being scarcely distinguish- 
able from one another. This ridged body is referred to by Owen I 
as probably having an olfactory function, and a similar view is 
expressed by Ray Lankester.§ Van der Hoeven|| dissents from 
this and expresses the belief that these folds are "only rudi- 
mentary digitations completing the circle of the internal labial 
processes." 
It seems somewhat remarkable that a connection of some kind 
with the function of reproduction should not earlier have been 
suggested for the entire inner tentaculiferous lobe with its 
* Memoir on the Pearly Nautilus, 1832. 
t Brorm's Thierreich, Malacozoa, III. Band, p. 1360. 
X Op. cit. 
§ Zool. Articles from the Encyclopaedia Britannica, Mollusea, p. 137. 
|| Trans, Zool. Soc. iv. 
