NOTES. 463 



probable that the polyphyletic hypothesis is nearer to the truth than 

 that which opposes it. 



-Vffc 115, page 301. These words had long been written when, quite 

 lately, a paper came into my hands by Huxley on the affinities of fresh- 

 water Crustaceans. According to him, the river Crustaceans of the 

 northern hemisphere belong to one family, called by him Patamcibtidee, 

 while those of the south he calls Parastacida:. He points out that the 

 two groups are easily distinguished by certain peculiarities in the struc- 

 ture of the gills, but he nevertheless suggests that the two forms, in 

 themselves so distinct, might have descended from a common primitive 

 form which peopled the tropical seas where they are now for the most 

 part wanting and in their migrations into the rivers of the islands and 

 continents of the north diverged into the structure of the Potamiibiidee, 

 and in the south into that of the Parastacidte. 



Note \\,page 302. A notice of Tyndall's recent investigations may 

 be found in Nature for 1877. The unprejudiced reader will here find, 

 as it seems to me, an irrefutable disproof of ' Abiogenesis,' as it is called, 

 and will be greatly interested in following the course of brilliant expe- 

 riments, and the crowd of new facts elicited by them. Any further 

 details are not here to the purpose, as Tyndall's experiments were made 

 on the development of the germs of Fungi. 



Note 117, page 312. In the centre of Mindanao, on the upper course 

 of the Agusan, among the Manobos living there, I found a fcssil 

 elephant's tooth, which was worn by the Baganis, or chiefs, of that can- 

 nibal race on solemn occasions, such as going out to battle, strung on to 

 a necklace with other objects, as small images of gods, crocodiles' teeth, 

 ice. ^Tien a foe is killed, his breast is opened with the sacred sword, 

 and all these objects, sacred to the god of war, are dipped in his blood ; 

 and it is not till the god has thus slaked his thirst in the blood of the 

 enemy that the Bagani may eat a portion of the heart or lungs. Both 

 the specimens of fossil elephant-teeth that I brought thence are now in 

 the Ethnological Museum at Dresden. 



CHAPTER XL 



-Vote l\,page 332. Compare Note 18 to Chap. HI. 



Xcrte 119, page 339? It was formerly supposed that the slightly spiral 

 tubes in the corals, in which the Sipunculidae live, were the shells of a 

 mollusc, and that the worms had first established themselves in them, 

 and then the coral had formed upon them. This view was the result of 

 a superficial examination ; there can be no doubt that the worm settles 

 on the coral, grows with it, and makes its own tube. 



