CHAP. XV. ON THE DROSERACE.E. 357 



alimentary canal ; but they live by absorbing through 

 root-like processes the juices of the animals on which 

 they are parasitic.* 



Of the six genera, Drosera has been incomparably 

 the most successful in the battle for life ; and a large 

 part of its success may be attributed to its manner 

 of catching insects. It is a dominant form, for it is 

 believed to include about 100 species,f which range in 

 the Old World from the Arctic regions to Southern 

 India, to the Cape of Good Hope, Madagascar, and 

 Australia; and in the New World from Canada to 

 Tierra del Fuego. In this respect it presents a marked 

 contrast with the five other genera, which appear to be 

 failing groups. Dioneea includes only a single species, 

 which is confined to one district in Carolina. The 

 three varieties or closely allied species of Aldrovanda, 

 like so many water-plants, have a wide range from 

 Central Europe to Bengal and Australia. Droso- 

 phyllum includes only one species, limited to Portugal 

 and Morocco. Eoridula and Byblis each have (as I 



* Fritz Miiller, ' Facts for Dar- condition, for it lias root like pro- 

 win,' Eng. trans. 1869, p. 1 39. The cesses embedded in the skin of the 

 rhizocephalous crustaceans are shark on which it is parasitic, and 

 allied to the cirripedes. It is hardly its prehensile cirri and mouth (as 

 possible to imagine a greater dif- described in my monograph on 

 ference than that between an ani- the Lepadidse, ' Ray Soc.' 1851, 

 mal with prehensile limbs, a well- p. 169) are in a most feeble and 

 constructed mouth and alimentary almost rudimentary condition, 

 canal, and one destitute of all Dr. R. Kossmann has given a very 

 these organs and feeding by ab- interesting discussion on this 

 sorption through branching root- subject in his 'Suctoria and Le- 

 like processes. If one rare cirri- padidse,' 1873. See also, Dr. 

 pede,the Anelasma squalicola, had Dohrn, ' Der Ursprimg der Wir- 

 bccome extinct, it would have belthiere,' 1875, p. 77. 

 been very difficult to conjecture f Bentham and Hooker, ' Genera 

 how so enormous a change could Plantaruiu.' Australia is the me- 

 have been gradually effected. tropolis of the genus, forty-one 

 But as Fritz Miiller remarks, we species having been described 

 have in Anelasma an animal in from this country, as Prof. Oliver 

 an ilmost exactly intermediate informs me. 



