374 ANNUAL BEPORT SMITHSONIAN INSTITUTION, 1911. 



The history of the Maltese family of Kelleia is often referred to 

 as an example of mutative changes in the case of human beings. 

 The father and mother of this family had the ordinary number of 

 toes and fingers, but their eldest son possessed six fingers on each 

 hand and six toes on each foot. This child, Gratio, subsequently 

 married and had children, several of them having six fingers and 

 toes. This malformation was absent in the following generation, 

 but reappeared in the succeeding family; it then seemed to have 

 died out. Another remarkable instance of this kind is that of the 

 flock of Massachusetts Ancon sheep. The deformity which charac- 

 terized these sheep, however, disappeared in the course of a few 

 years, it is said in consequence of the introduction of the Merino 

 sheep into the United States. In both these cases of the sudden 

 development of monstrosities it can not be said that new species, 

 but only varieties, had suddenly come into being. Our knowledge, 

 however, concerning the evolution of the simpler into complex 

 orders of plants, like that of animals, must to a large extent be 

 guided by information we derive from the study of their fossil re- 

 mains — a branch of science which has only been taken seriously in 

 hand within the last few years. Palaeobotanists of repute, such as 

 MM. Barrois, Bertrand, and Cayeux, are of opinion that in the 

 earliest sedimentary or pre-Cambrian formations they have obtained 

 evidence of the existence of rudimentary animals and plants, in the 

 shape of protophytes and protozoans. 1 However this may be, we 

 know that numerous species of diatoms, seaweeds, and fungi exist 

 in a fossil state in the coal measures of England and other parts 

 of the world, and that the structure of these beings resembled those 

 now flourishing. The higher plants, however, on which these fungi 

 fed "have changed profoundly since" the coal-measure epoch, 

 "stimulated by ever-changing surroundings." 2 All the plants 

 which existed during the Carboniferous period have become extinct; 

 they were flowerless and otherwise differed from those of the present 

 day; but this difference was in outward form, or the grouping of 

 their cells, rather than in the functions performed by their vascular, 

 respirator}^, and other structures. Thus we find in fossil plants of 

 our coal measures a layer of chlorophyll bearing cells situated 

 beneath their epidermis, indicating the existence of a starch-forming 

 system, worked by energy derived from sunlight. In each succeed- 

 ing geological period the main types of vegetation changed, and 

 each succeeding change advanced a step toward the types of the 

 existing flora. 3 It was not, however, until we arrive at the Creta- 

 ceous epoch that the existence of fossil flowering plants appear. 



1 Annual Report of the Smithsonian Institution for the year 1903, p. 512. 



2 Ancient Plants, by M. C. Stopes, D. Sc, p. 165. 

 s Idem, p. 40. 



