324 OKIGIN OF LIFE IN AMERICA 



the essential unity of the area inhabited by the snail Placo- 

 stylus,* thus regarding New Zealand and the archipelagoes of 

 Solomon, Fiji, New Hebrides, Loyalty, New Caledonia and 

 Lord Howe as portions of a shattered continent which he 

 called the " Melanesian plateau." The short review on the 

 subject by Dr. Holdhausf in favour of a Pacific Continent in 

 Tertiary times adds little to the arguments already advanced 

 by Professor Baur. 



A most determined and thoroughgoing onslaught on the 

 theory of a supposed former Pacific Continent was recently 

 made by Mr. Guppy. It seems scarcely fair to compare the 

 results of his studies with those just alluded to, because 

 he derives his arguments almost altogether from the flora 

 of the Pacific islands, while the others were founded on 

 faunistic data. Still, Mr. Guppy's works $ contain a great 

 deal of personal observation, and his carerul labours in 

 this particular field of enquiry will be sure to attract 

 the serious attention of the student of geographical dis- 

 tribution. His discussion of the subject is disappointing 

 in some respects. " If the distribution of a particular 

 group of plants or animals does not accord with the pre- 

 sent arrangement of the land," he remarks, " it is by far 

 the safest plan, even after exhausting all likely modes of 

 explanation, not to invoke the intervention of geographical 

 changes." A little further he explains " I scarcely think 

 that our knowledge of any one group of organisms is ever 

 sufficiently precise to justify a recourse to hypothetical altera- 

 tions in the present relations of land and sea." In reading 

 such passages one wonders whether Mr. Guppy can have 

 become acquainted with the science of geology, or with the 

 principles that underlie the geographical distribution, for 

 example, of mammals. His opinions differ radically even from 

 those of Dr. Wallace, who cannot be said to have been unduly 

 rash in any of his conclusions as to former changes of land 

 and water. One would also expect from Mr. Guppy an abun- 

 dance of important facts concerning the dispersal of seeds 

 by the various means of accidental transport. But he tells us 



* Hedley, C., " Bange of Placostylus," p. 339. 



t Holdhaus, K., " Argumente f . d. Existens eines pazif. Kontinents." 



J Guppy, H. B., "A Naturalist in the Pacific," I., p. 380. 



