1873.] THE RED BLOOD-CORPUSCLES OF BA.TRACHIANS. 163 



the subject, this will not be attempted at present Only I remember 

 that Rudolph Wagner long since discovered the large size ot the red 

 blood-corpuscles of Proteus, and Van der Hoeven soon afterwards 

 their almost equal magnitude in Cryptobranchus japomcus, that 

 Riddel quite recently proved their preeminent largeness mAmphtuma, 

 and that they were originally examined and measured and their 

 Batrachian character shown by me in Lepidosiren. Of some ot the 

 animals mentioned in the present Table, the blood-corpuscles, so tar 

 as I know, have not been previously examined. 



Lepidosiren is here placed among the Batrachians, not to imply 

 any view as to its true position, but merely because this paradoxical 

 creature has blood-disks like in size to those of a Batrachian, and 

 unlike, in this respect, to those yet known of any regular fash. 

 Cryptobranchus japonicus is the same as Sieboldia maxima ot the 

 following Table, and of some of the former 'Proceedings of the 

 Society. 

 Table of Measurements of the Red Blood-Corpuscles of Batrachians. 



According to my invariable practice, all the measurements are ex- 

 pressed in vulgar fractions of an English inch ; and of the corpuscles 

 the long diameter is denoted by L. D., the short diameter by 8. D., 

 and the thickness by T. The average sizes only are given ; but it 

 should be understood that many are a third larger and a third smaller 

 than the mean, and a few occasionally still more deviating from it, 

 while there is every gradation of size between the extremes ; still 

 the majority of the corpuscles are of the average size. And all this 

 is true of the red blood-corpuscles of most vertebrates. The animals 

 are here set down in the order of the largeness of these corpuscles, 

 except when this would confuse species of different genera ot the 

 Frogs and Toads. 



j_ JL 



Amphiuma tridactylum 36a 615 



Nucleus 1143 2000 



1 _1_ 



Proteus anguinus 400 727 



Nucleus 16oo 2666 



Siren lacertina 420 760 



1 1 



Nucleus ii42 2007 



1 j_ 



Sieboldia maxima 450 soo 



Menopoma alleghaniense 563 iooo 



Nucleus 1333 2286 



1 J_ 



Lepidosiren annectens gjo 941 



Nucleus 1555 2900 



1 J_ 



Siredon humboldtn gfi 1000 



Nucleus 2ooo 3000 



11* 



