96 The Penguins 



obtained by the Swedish South Polar Expedition on Seymour Island only about 

 two degrees below the Antarctic Circle, and the remainder by Dr. Florentino 

 Ameghino in Patagonia, all, it is believed, in beds of Miocene age. 1 These re- 

 mains have been studied by Drs. Wiman and Ameghino with the astonishing 

 result of showing apparently that the earlier forms of Penguins, so far as shown 

 by their limbs and especially by the tarsi, were much more generalized than the 

 living species. The tarsi, while comparatively longer in the fossil species than 

 in the living forms, had their component bones much less clearly indicated than 

 in modern Penguins, which is exactly the opposite of what should prevail, if, as 

 has been supposed, the tarsus of the living Penguin is a survival of the primitive 

 free condition of these bones. In other words, it appears that the present-day 

 Penguins, with their uniquely free tarsal bones, have been derived from forms in 

 which these bones were more or less consolidated, which naturally brings them 

 closer to ordinary carinate birds in which the tarsal bones are practically solid. 

 This consolidation of the tarsal bones is possibly an adaptive feature which has 

 perhaps been brought about " by the habit of sitting with the tarsus on the ground 

 when at rest." 



The relationship between the Penguins and other birds is rather hard to make 

 out. Professor Watson, who studied the extensive material obtained by the 

 Challenger expedition, regards them as the surviving members of a group that 

 branched off early from the primitive "avian" stem, but "at the time of their 

 separation the stem had diverged so far from reptiles as to possess true wings, 

 though the metatarsal bones had not lost their distinctness and become pressed 

 into the single bone so characteristic of existing birds." Pycraft has studied 

 the anatomy of the group more recently, and, while he recognizes the fact that 

 the skeletal specialization has reached the high-water mark, it does not, he claims, 

 take us beyond the confines of the Class. He says: "Osteologically the Penguins 

 seem to be nearly related to the Tubinares and Pygopodes, and, as Gadow and 

 others have shown, the evidence of the soft parts confirms this supposition." 

 Dr. Stejneger considers that the Penguins should be placed in a group of equal 

 rank with the Ostriches and their allies, and the rest of living birds, that is to say 

 that existing birds should be divided into three groups, of which the Penguins 

 should constitute one. Others, and more especially Gadow, whotn we are follow- 

 ing, regard the characters as of somewhat less importance and would only accord 

 them ordinal rank. Apparently we must look to paleontology for further light 

 on this perplexing point, and this, as already pointed out, seems to indicate that 

 the line separating them from carinate birds in general is less sharp than was 

 formerly supposed. 



Species. About twenty living species of Penguins are known. They are 

 confined exclusively, as already stated, to the Antarctic region, never crossing 

 and rarely even approaching the equator. They are, perhaps, most abundant 

 in species in the vicinity of the Falkland Islands, but they do not range north 



1 Cladornis pachypus, also from the Patagonian Miocene, is regarded by Ameghino as repre- 

 senting a divergent type of Penguin with a very thick leg, but it is imperfectly known, and seems 

 hardly to belong here. 



