740 



THE HARVEIAN ORATION. 



but with an older stock, the many-sided potentialities of which 

 embraced not only mammals, but all warm-blooded animals, and 

 not only all warm-blooded creatures, but warm-blooded animals and 



Fig. 3. — Heart of Australian Cassowary (Casuarius australis), prepared 

 similarly to the heart of sheep, figured in Figure 2, and showing at M the 

 moderator band. A line of papillary upgrowths is indicated at the upper 

 end of the upper segment of the muscular auriculo-ventricular valve, passing 

 downwards towards the point of origin of the moderator band from the 

 septum. They extend in the specimen over a space of about three- eighths 

 of an inch, and are indicated in the woodcut by dark transverse lines. 



reptiles also ? The valves of the heart in the higher vertebrata, 

 when regarded from this j-oint of view of development — the safest 



