100 PROF. GULLIVER ON THE RED CoRPUSCLES ([Feb. 25, 
of Vertebrata, comprehending such a wide extent of subordinate facts 
as to rise to all the dignity of a central one, small as it may appear, 
is really a great addition to zoological science. Thus is plainly un- 
folded the most universal and essential difference ever before dis- 
covered between the Mammalia and oviparous Vertebrata ; for this 
one minute point is in truth so large and extensive as to clearly cha- 
racterize the divisions in question in any sex or at any age, which 
not one of the old diagnoses can effect. Yet not even a glimpse of 
this important truth, so readily reconciling the discrepancies of former 
observers, was ever caught, during the contentions as to the presence 
or absence of the nucleus, in this zoological point of view. 
And the present conclusion is alike extended and supported by the 
discoveries of development for which we are indebted to Mr. Wharton 
Jones, who has clearly shown that there is a similar difference in 
this respect. But although his important researches ought to have 
been well known in this country since 1845, they have been strangely 
neglected, while the far less accurate and comprehensive observations 
of Professor K6lliker have been imported and translated, and much 
too generally adopted in England. In connexion with Mr. Wharton 
Jones’s conclusion, I may mention that one, two, three, or four mam- 
malian red corpuscles may certainly form a nucleus of a cell, as 
depicted by me in the ‘ Philosophical Magazine,’ Sept. 1842, p. 170. 
This observation has often since been imported from abroad, but 
never with the least perception of its significance. 
And so “this vexed question of.a nucleus” is at length not only 
settled, but also placed at the service of systematic zoology. Ac- 
cordingly, the two great divisions of the Vertebrate subkingdom are 
here characterized as Vertebrata pyrenemata and Vertebrata apy- 
renemata—the former corresponding to the oviparous, and the latter 
to the Mammalian section. 
DESCRIPTION OF THE WOOD ENGRAVING (p. 101). 
All the corpuscles are drawn to a scale of ;;4>5th of an English inch, and are 
magnified about 920 times linear admeasurement. The scale is marked at the 
bottom of the engraving. : 
Corpuscles only of average size are.given ; and but one corpuscle from each 
species of animal, with the few exceptions presently to be noticed. 
The corpuscles of Apyrenzematous Vertebrates occupy the upper part of the 
engraving, above the double line ; and the different orders of these are separated 
by the short upright lines. The corpuscles of Pyrenzematous Vertebrates occupy 
all the larger part of the engraving below the double line. At 12 is a row of 
birds’ corpuscles; 13-17, corpuscles of reptiles ; and 18, a row of the corpuscles 
of fishes. The figures at 1 and 12, referring to structure, are fully explained at 
page 93. Of the Pyrenzmatous Vertebrates, the nuclei are shown much more 
plainly than they appear in the pure corpuscles; but the action of acetic acid ex- 
poses the nuclei as distinctly as they are here represented. 
The names of the animals are set down in the following table, according to the 
order in which the sketches of the corpuscles stand in the engraving. The fol- 
lowing measurements of the corpuscles are all in vulgar fractions of an English 
inch; but as the numerator is invariably 1, it is omitted throughout, and the de- 
nominators only are printed. T. denotes the thickness, L. D. the long diameter, 
and §S. D. the short diameter of the corpuscles. 
