134 



HA RD WICKE'S SCIENCE- G OSS IP. 



3. Listophoridos may be considered as the con- 

 necting link between the Dermaleichidae and the 

 Scaroptidre. The commonest species, L. gibbus, is 

 found on the hare and rabbit, often in large numbers. 

 In connection with this parasite, though belonging to 

 a different class, may be mentioned the Cheyletus 

 parasitivorax, also found on the rabbit and hare, and 

 whose vocation in life it is to live not upon the hare 

 or rabbit, but upon the species of L. gibbus already 

 mentioned, the hare or rabbit merely forming the 

 happy hunting-ground. 



4. Sarcoptidge, or itch-mites, which are allied to 

 the last sub-genera in many respects, but differ from 

 them in their habits, and also in being injurious to 

 their hosts. These mites, of which there are a 

 number of varieties, all burrow below the skin and 

 live, multiply, and die there. The common fowl is 

 affected with one species ; the mange of the horse is 

 caused by a second ; while the disease of sheep known 

 as scab is occasioned by a third. All are of small 

 size, and resemble in appearance the A cants scabiei, 

 specimens of which are to be found in most collections 

 of microscope slides. 



5. Hypopidae. — There has been a good deal of 

 controversy regarding this sub-genus, as to whether it 

 is a distinct species or only the transition stage of 

 some other Acarus ; but into this discussion it will be 

 unnecessary to enter. The two best-known species 

 are //. muscarum (see Fig. 92), from the fly, and //. 

 arvicola, from the field-mouse. In the above sketch 

 many interesting species have had to be passed over, 

 such as the genus Myobia, found on the mouse, and 

 the Demodex, found in the pores of the skin. 



GOSSIP ON CURRENT TOPICS. 

 By W. Mattieu Williams, F.R.A.S., F.C.S. 



A TORTOISE PARASITE. — Mr. Hyslop's 

 " Chapters on Animal Parasites " reminds me 

 of a curious creature I found adhering to the leg, or 

 rather between the leg and abdomen, of a tortoise 

 that had lived for some time in my garden. It was 

 similar to a sheep-tick, but much larger— about the 

 size of a shilling, but oval — with light fawn-coloured 

 back and belly, and short dark legs. In shape and 

 general appearance it curiously resembled its host, 

 to the hard warty skin of which it was very firmly 

 hooked, after the usual habit of these amiable 

 creatures, whose beneficent agency is not satisfac- 

 torily defined in any of the Bridgewater Treatises. 

 I make a note of finding this animal, as it strikingly 

 illustrates the universality of such pests ; a tortoise 

 with its hard shell and small exposure of horny skin 

 being apparently so well protected. Mr. Ilyslop 

 will probably tell us something about other similar 

 creatures. It appears to me that the parasites of 

 reptiles have been but little studied. Do the scales 



of a crocodile completely protect him from their 

 attacks ? 



Saccharin. — Many paragraphs have lately ap- 

 peared concerning this substance. In these it is 

 described as something quite newly discovered. This 

 is a mistake. It was discovered in 1879 by Fahlen- 

 berg and Remsen, who named it anhydro-orthosul- 

 phaminebenzoic acid, in accordance with the descrip- 

 tive practice which I have already discussed in 

 previous gossip. It was obtained by the oxidation 

 of orthotoluenesulphonamide. Experiments have 

 been recently made by Stutzer in order to ascertain 

 whether its remarkable sweetening properties may 

 become practically useful. He sweetened the food 

 of rabbits and dogs with it, watched its effect on the 

 animals, and observed nothing injurious. It passed 

 through the bodies of these animals without change. 

 It is so intensely sweet that one part dissolved in 

 10,000 parts of water perceptibly sweetens it. It 

 has in addition a slight almond flavour. Stutzer 

 concludes that it will in future be used instead of 

 cane sugar for sweetening pastry, liqueurs, medi- 

 cines, etc. 



I am very sceptical concerning the desirability 

 of using it for sweetening any kind of food. The 

 dogs and rabbits were not killed, but, being unable 

 to answer questions concerning the state of their 

 health and feelings, their evidence is of little value. 

 The introduction of a foreign substance which passes 

 through the body without being assimilated or other- 

 wise changed may not produce violent mischief, but 

 it must act somehow if it has any decided chemi- 

 cal energies ; and any interference with the normal 

 healthy actions of the bodily functions is likely to be 

 damaging rather than beneficial. The most plausible 

 excuse for using this substance is for sweetening 

 the food of diabetic, gouty and other patients, who 

 may be injured by using sugar. There is however 

 a much safer mode of overcoming this difficulty — 

 that of resisting the childish craving for sweeties and 

 sweetening, which is easily done by simple abstinence. 

 I have met with several cases of men who have thus 

 abstained ; all have found, after a while, that their 

 desire for sugar was an acquired habit, and that 

 finally they preferred their tea, coffee, etc., without 

 sugar. 



The name of saccharin, as now applied to this 

 substance, is unfortunate, this name having been 

 applied in 1880 to the carbohydrate obtained by the 

 action of lime on common cane sugar. 



Poisonous Cheese. — In 1883-4 as many as three 

 hundred persons were taken ill in Michigan after 

 eating certain cheeses ; the symptoms were vomiting 

 and purging, followed by signs of failure of the heart, 

 and nervous prostration. The cheeses had no special 

 or peculiar flavour, but when cut a slightly opalescent 

 acid fluid exuded. Dogs and cats refused to eat 



