ESTIMATE OF ARISTOTLE 155 



This year, too, Huxley completed his Introductory 

 Primer to Macmillan's Science Primer Series, but it did not 

 appear till the following year. 



Two scientific memoirs of the year are as follows : — 



1. " On the Characters of the Pelvis in the Mammalia, 

 and the Conclusions respecting the Origin of Mammals 

 which may be based on them " (Proc. Roy. Soc, xxviii, 

 1879, pp. 395-405. Read March 6, 1879. Sci. Mem., 

 iv, XIX, p. 345). — That Mammals have descended from 

 Amphibians is the conclusion at which the memoir 

 arrives. It has now been superseded by the theory of a 

 reptilian origin. 



2. '' On Certain Errors respecting the Structure of the 

 Heart attributed to Aristotle " (Nature, xxi, 1 879, pp. I-5. 

 Sci. Mem., iv, xxii, p. 380). — It is illustrative of Hux- 

 ley's untiring energy that in late middle life, in spite of 

 exacting and numerous activities, he should begin the 

 study of Greek, actuated with the desire of studying 

 Aristotle and the Greek Testament first hand. The 

 paper now under consideration was one result of this 

 self-imposed task. 



Aristotle describes the mammalian heart as consisting 

 of three instead of four chambers. The explanation is 

 that what is now called the right auricle was considered 

 to be a swelling of the great veins. The following 

 estimate of Aristotle's powers as a naturalist finds a place 

 in the paper : — 



" He carried science a step beyond the point at which he 

 found it ; a meritorious, but not a miraculous, achievement. 

 What he did required the possession of very good powers of 

 observation ; if they had been powers of the highest class he 

 would hardly have left such conspicuous objects as the valves 

 of the heart to be described by his successors." 



