376 Morgan and Tallmon — Occurrence of Bitumen. 



the organic matter still retained essentially its original char- 

 acter." 



The attempt has been made repeatedly to realize these condi- 

 tion, — to ascertain whether unquestioned evidence could not 

 be obtained to show from what kind of matter natural deposits 

 have actually been derived. Many natural deposits have been 

 carefully examined, but in no case can the evidence be con- 

 sidered as conclusive. 



Thus, Wall pronounced the celebrated ''pitch lake" of Trini- 

 dad to be of vegetable origin because of the remains of vegeta- 

 tion in all stages of transition which are present in the pitch. 

 Jones found in the same pitch unquestionable animal remains ; 

 hence an animal origin is not improbable. Later Richardson* 

 examined the " lake " and concluded that the conditions pre-, 

 sent offer " a far more reasonable basis for the assumption of a 

 volcanic origin." 



Fraas observed petroleum oozing from a coral reef in the 

 Red Sea and concluded that the coral polyps are to-day being 

 changed into bitumen. Binney noticed the same phenomenon 

 about a peat bog in England and inferred that peat was being 

 transformed at the present time into petroleum. Both of these 

 are isolated instances. No other known coral reefs or peat bogs 

 show evidence of similar changes, although conditions seem to 

 be identical. Neither occurrence was thoroughly studied "to 

 ascertain what evidence there might be for or against the pos- 

 sibility of another origin. Neither instance is to be regarded, 

 therefore, as unquestionable. 



The occurrence of bitumen in fossils has hitherto been of no 

 value as a means of furnishing direct evidence as to its origin, 

 inasmuch as investigation proves that the bitumen need not, 

 and often could not, have been derived from the organism with 

 the remains of which it is to-day associated. 



The discovery of the present specimen, a fossil egg partly 

 filled with bituminous material, is under these circumstances of 

 scientific value. For while absolute proof cannot be given, 

 the evidence amounts almost to a demonstration that the bitu- 

 minous substance now present in the egg represents a part of its 

 original organic contents. In the absence of any evidence to the 

 contrary we may accept that origin toward which all the evi- 

 dence points. This specimen presents, then, one of the very few 

 instances, possibly the only one, in which conclusive evidence 

 is at hand to connect bituminous matter with the original 

 material from which it has been derived by a natural process 

 without abnormal conditions. 



The absence of nitrogen from a bitumen material can not be 

 regarded, therefore, as unquestioned evidence of its vegetable 



*Jour. Am. Chem. Soc, 7-51 (1893). 



