382 



Annals of Medical History 



The remains of the early vertebrates 

 prior to the Permian have shown no note- 

 worthy pathological lesions. There may 





Fig. 1. Parasitized stem of a crinoid, from the 

 Carboniferous of Germany, showing the tumor- 

 like mass produced by the action of the myzostomid. 

 (After Graff.) 



Fig. 2. Portion of parasitized crinoid stem, show- 

 ing carbonized remains of the myzostomid. (After 

 Graff.) 



Fig. 3. Section through a fossil coral, Pleurodic- 

 tyum problematicum from the Lower Devonian of 

 Eifel, showing the worm tube near the center. 

 An example of ancient commensalism (After 

 Stromer von Reichenbach.) 



Fig. 4. An enlarged stem of a crinoid from the 

 Keokuk beds of North America, showing that 

 the enlargement has involved the plates of the 

 stem. This specimen was thoroughly mineralized 

 into a geode, so that no evidences of the parasite 

 were seen. One-half natural size. 



have been diseases among these early 

 forms, but the lesions have not yet been 

 discovered. We find, to be sure, certain 



laterally compressed fishes preserved in the 

 attitude of the opisthotonos and pleuro- 

 thotonos in horizons prior to the Permian. 

 These attitudes may have been due to 

 spastic distress induced by cerebrospinal 

 infections or to some form of poisoning. 

 Since this subject will be more fully treated 

 elsewhere nothing more need be said than 

 that these attitudes possibly represent dis- 

 eased conditions of the central nervous 

 system. 



PATHOLOGY OF THE PERMIAN VERTEBRATES 



Several pathological conditions are indi- 

 cated among the vertebrates of the Per- 

 mian. Renault 32 has described caries of 

 certain fish bones preserved in coprolites 

 from the Autun basin. He concludes that 

 this type of caries is due to several types of 

 bacteria which he has described and figured. 

 A left radius of Dimetrodon, a primitive 

 reptile, from the Permian of Texas shows 

 an incompletely healed fracture (Fig. 5) 

 with abundant osteosclerosis and some in- 

 termediary callus. This is the oldest known 

 case of fracture. It was a simple fracture 

 cutting the bone at right angles, and the 

 healing process has taken place with very 

 little shortening. The bone has no medullary 

 cavity, so that attempts to study the nature 

 of the fracture by means of the x-ray have 

 been a failure. The Texas red beds, from 

 which the bone comes, are impregnated 

 with iron, and the radius reacts to the 

 x-rays much as a bar of iron would. A 

 fractured rib with an old callus is also 

 known from the Permian of Texas. A 

 description of this lesion with illustrations 

 is to be found in The Surgical Clinics of 

 Chicago, April, 19 18. Von Huene has de- 

 scribed the skull of a phytosaur from the 

 Triassic of Germany, showing a fractured 

 snout with many necrotic sinuses. 



32 B. Renault: "Microorganismes des combustibles 

 fossiles," Bull. Soc. de l' Industrie minerale a Saint- 

 Etienne,- 1899-1900, Ser. Ill, with atlas of plates. 



