378 



Annals of Medical History 



Carboniferous vascular plants, and the 

 scarcity of described forms must be attri^ 

 buted to the perishable nature of most 

 fungal tissues and to the lack of syste- 

 matic work by experienced mycologists 

 on the more or less obscure material avail- 

 able. To be sure, quite a considerable 

 number of fossil forms referred to Fungi 

 have been recorded from various geologic 

 horizons but the vast majority of these 

 are leaf-spot types based upon real or 

 fancied resemblances, and found on im- 

 pressions of foliage and without definite 

 botanical characters. Some doubtless rep- 

 resent fungal ravages, others are due to 

 insects, some are glandular, and others 

 are purely imaginary." 



Professor Berry refers to A. Meschinelli's 

 "Fungorum Fossilium Omnium Iconograph- 

 ia," (1902, 144 pp., 31 plates), for a rather 

 complete illustrated list of all of the forms 

 referred to down to the year 1900. Other 

 and more complete studies on the bacteria 

 and fungi of the Coal Measures of France 

 particularly have been made by Van Tieg- 

 hem and Renault. A fairly complete list of 

 their numerous papers is to be found in 

 Smith's bibliography. 17 Other information 

 may be gleaned from the memoirs and text- 

 books dealing with Paleobotany. 



17 Erwin F. Smith: "Bacteria in Prehistoric 

 Times." In "Bacteria in Relation to Plant Diseases," 

 1905, vol. 1, p. 262. 



18 The question of extinction is still one of the 

 unsolved problems of paleontology. The importance 

 of those diseases which leave an impress on the 

 skeleton has been referred to by the author in the 

 following words: 



"It is not my intention to contend that disease 

 has not been influential in the extinction of races 

 (or species); it probably has been; but those diseases 

 which have left an impress on the fossilized skeleton 

 certainly cannot be regarded as among those 

 diseases which would produce widespread extinc- 

 tion. Some other has been the dominant factor. 

 The present results of the study of fossil pathology 

 indicate the early appearance in geological time 

 and widespread distribution of diseases of many 



METCHNIKOFF ON DISEASES IN 

 REMOTE EPOCHS 



The possible presence of disease among 

 animals of remote epochs of the earth's his- 

 tory was suggested by Elie Metchnikoff 

 in the following words: 



"Diseases in general and infective dis- 

 eases in particular were developed on the 

 earth at a very remote epoch. Far from 

 being peculiar to man, animals and the 

 higher plants, they attack inferior forms 

 and are widely distributed among uni- 

 cellular organism, Infusoria and Algae. 

 Diseases undoubtedly play an important 

 role in the history of life on our planet, and 

 it is very probable that they have con- 

 tributed in a marked degree to the ex- 

 tinction of certain species. 18 When we 

 observe the ravages produced by para- 

 sitic Fungi among the young fish which 

 we are trying to rear, or the destruction 

 of cray-fish in certain countries in con- 

 sequence of the rapid increase of epizootic 

 germs, we are involuntarily led to the 

 conclusion that pathogenic micro-organ- 

 isms must have brought about the dis- 

 appearance of certain animal and vegeta- 

 ble species." 19 



It would be interesting in this connection 

 to know Metchnikoff's sources of informa- 

 tion relative to the presence of diseases at 

 remote epochs. Virchow's studies on the 



kinds, but none of them, so far as the fossil lesions 

 may be interpreted, were sufficiently severe to 

 have played a part in the extinction of any of the 

 known groups of fossil vertebrates. They are to be 

 regarded rather as chronic infectious or constitu- 

 tional diseases which may have played a part in 

 extinction, but there must have been some other 

 and more powerful ally which is at present un- 

 known." ("The Influence of Disease in the Ex- 

 tinction of Races," Science, N. S., Jan. 19, 1917, 

 vol. xlv., No. 1 151, pp. 63-64. 



19 Elie Metchnikoff: "Immunity in Infective 

 Diseases," 1915. Translated from the French by 

 Francis G. Binnie, p. 8. 



