588 The Sensory Organs. [ September, 
described them more minutely. He corroborated the general 
statements of Max Schultze with regard to the hair-bearing epi- 
thelium, stating that the hairs are so very perishable that they can 
only be observed in fresh preparations. He finds on the floor of 
the vesicle three small eminences lying in the direction of the 
fibrous attachment, the middle one being the larger. These are 
constituted by cylindrical epithelial cells and the perceptive cells, 
while the rest of the vesicle is lined by a flat epithelium. The 
nerves are distributed exclusively to the emznences, and are, as 
Boll thinks, probably continuous with the perceptive cells. These 
bear peripheral and central processes. 
Regarding these organs Max Schultze (Abh’dl’g. d. N. ges. zu 
Halle. 1863) makes the following interesting remarks: “As they 
are closed vesicles and lie somewhat deeply hidden, we can look 
upon them as the transitional forms between feel-hairs ending 
freely in the water and which are possessed by fishes and naked 
amphibians, and the nerve-hairs of the ampulle of the organ of 
hearing. In this last, the arrangement of the nerve-endings for 
the perception of sound waves from the endolymph, is evidently 
so similar to the structure in the Savian vesicle, that the question 
might arise whether the latter belongs to the sound perceiving 
organs. As the electric ray possesses very well-developed organs 
of hearing in the shape of otolith saccules and semicircular canals, 
there are no grounds for ascribing yet another organ of hearing 
to it. Therefore we adhere to the supposition that the Savian 
vesicles are a special modification of the organs of common sen- 
sation. .. .” Further on, he says that they probably appreciate 
coarse waves or vibrations in the water. 
A very significant fact, and which probably brings the side 
organs or mucous canals, the Savian vesicles and organ of hear- 
-ing into the same category, is the following: The Savian vesicles 
are supplied by the fft% pair of nerves, while the mucous canals 
or side organs are supplied by the lateral nerves, which again are 
made up largely of the fifth, in some fishes almost entirely; and a 
most remarkable fact, but one which is entirely explainable by 
l embryological datá, is, that in one fish, the skate (Owen, Comp. 
a my the y nerve is apparently a primary branch of the 
JJA! 
Now, while bearing the facts with regard to the sensory organs 
in th ee of fishes and amphibians in mind, let us see 
