262 FROM THE GREEKS TO DARWIN 



induced in the egg by external influences — acci- 

 dents, as it were, regulated by law. As it involved 

 rapid, as well as gradual, transformation, St. 

 Hilaire's system did not always require the ex- 

 istence of intermediate hnks. For instance, he 

 advanced as an hypothesis the fantastic sugges- 

 tion that the first bird might have issued directly 

 from the egg laid by a reptile, and, as a bird 

 could not be fertiUzed or intercrossed by its rep- 

 tilian relatives, the new characters could not be 

 suppressed by intercrossing: 



It is evidently not by an insensible change that the 

 inferior types of oviparous vertebrates have given 

 rise to the superior organization of the group of 

 birds. An accident, within the range of possibility, 

 and not very great in its original production, but of 

 an incalculable importance in all its effects, has suf- 

 ficed to produce in all parts of the body the condi- 

 tions of the bird type. 



Finally, his attitude toward transformism, 

 as explaining all forms of life, was much less 

 positive and sweeping than Lamarck's. His view 

 of degradation may be summed up in this sen- 

 tence: "Species vary with their environment, and 

 existing species have descended by modification 

 from earlier and somewhat simpler species." He 

 admitted that the question to be decided by fu- 

 ture palasontological research is whether "the 



