''j'^lLjmTim'] I^oyal Microsco^pical Society, 211 
certain families or species from other allied families or species.* 
To the same effect also were the results of my extension of the 
inquiry to cell-characters in plants. f "Inherent specific differences," 
says an eminent physiologist, " are to be demonstrated in the com- 
ponent cells of species as distinctly as in the entire organism ; and 
the more minutely investigation is carried, the more remarkable do 
these differences appear, and the more numerous do they become.''^: 
Even so. And the early and important labours in this direction of 
the late John Quekett, if not lost to science, are too often ignored 
in our books of comparative anatomy. 
Finally, it results from the present observations that positive 
differences exist between the lens-fibres of some Cyclostomi and the 
lens-fibres of many Teleostomi. But the precise value of these 
characters in systematic ichthyology remains^ to be determined by 
further observations. 
Fig. 1. — Portions of lens-libres of Petromyzon fiuviatilis; the fibres e^th of an 
incli iu diameter, which is the most common ^nd average size. 
„ 2.— The same from a lens whicli had been boiled in water. 
„ 3.— Bit of lens-fibre of Anguilla acutirostris ; diameter of the fibre awoth 
of an inch, being the average size. 
4.— The same of Esox Lucius ; the fibre a^oo^li of an iuch in diameter. 
Canterbury, Jan. 80, 1869. 
* Rodentia may be distinguished by the sheath of striped muscular fibre on 
the lower part of the sesophagus from Quadrumana and some other orders ; and 
in the dissections of the Aye-Aye (CMromys madagascariensis) it is to be regretted 
that it was not compared in this respect with these two orders to which zoologists 
have assigned this singular animal. But since this note was printed, I have 
examined the sesophagus of the Aye- Aye, which agrees with that of Quadrumana, 
as will be particularly described in the Proceedings of the Zoological Society. 
t ' Popular Science Review,' iv., 568. 
X Professor Beale, ' Trans. Microscop. Soc.,' 1864, N. S., xii., 33. 
