'J4 natural history. 



fore nobody has any motive for hunting them. I have not got any 

 " Sea-mouse " here. 



Of the Nematelmia, the most noticeable is the guinea-worm 

 (Filaria medinensis) which is unfortunately very abundant. How 

 it gets into the human body is not yet certainly known, but one 

 consideration points to its getting through the skin. It has been 

 known, though rarely, to attack the horse (and, I have heard, the 

 dog). Now these creatures don't usually take as much care about 

 what they drink as men do; and if drinking water was the usual 

 vehicle of the guinea-worm, they might be expected to suffer 

 much more frequently than men. But on the assumption that the 

 worm gets through the skin, the comparative immunity of dogs and 

 horses, which have much thicker skins than men (and also hair on 

 them) is easily accounted for. European authorities consider that 

 the guinea-worm doesn't appear until more than ten months or a 

 year after -it effects a lodgment. The natives, however, say that 

 three months is sometimes enough; and the circumstances of a very 

 bad outbreak in my own camp seemed to point to that period. 

 Probably the time may vary. Dr. Bastian considers the guinea-worm 

 to be only accidentally parasitic, and in that case, particularly, much 

 irregularity in development would be natural enough. 



The size of this worm is a good deal exaggerated in conversation ; 

 one of 30 inches is a good specimen. Nobody has ever seen a male 

 guineaworm to swear to him ; our unwelcome visitors are all 

 "ladies in an interesting condition"; and the young, even if liberat- 

 ed in the tissues by the breaking of their parent in extraction, do 

 not appear to grow. The common belief that they do is due to the 

 frequent presence of several filaria3 at one time in the patient, quite 

 independent one of the other. The breaking of the worm, there- 

 fore, is by no means such a serious misfortune as people make out. 

 The worst that comes of it is the prolongation of the business ; and 

 that, of course, is often quite bad enough. I knew of one case in 

 which the worm was broken, and the greater part of it never 

 extracted at all ; but the wound healed over, and the patient suf- 

 fered no more from it. The young, of course, were all or mostly 

 removed by pressure on the wound. 



Amongst the Echinodermata, I have not found here any Holothu- 

 ridae, or " sea-cucumbers." Probably we have some, but their 

 great head-quarters are in the Coral seas, whence they go to China 

 under the name of trepang, or B£che de mer, to be turned into soup. 



