THE AXIJiIAL LIFE OF THE GROUP. 401 



nine species, all belonging to one family,'* have been determined, six of which 

 are alreadj' known from the British Isles. But as the largest species "*• is but 

 a millimeter in length and has only been reported from Kona, on Hawaii, they 

 are too small to attract attention from collectors. As they occur, however, it 

 is well to know that the common species "" appears to be generally disti-ihuted 

 throughout the mountains of the group. 



Most of the ticks are small eight-legged creatures, though the number of 

 legs vary with age and the mode of life of the parasite. The chicken mite is an 

 example that occurs in Hawaii on poultry ; the dog-tick *i on the dog ; the so- 

 called red spider **- occurring on cotton plants, and the true itch mite,** causing 

 an irritation of the skin of human beings known as itch, are well-known 

 examples of the species of the order. 



Fleas. 



The flea is a tiny insect belonging to the order Siplionaptrra. and is sug- 

 gestive of the household pests of which Hawaii has its full quota. As has been 

 the case with the insects affecting the field, forage and garden plants and oi;r 

 domestic animals, the household pests have practically all been introduced 

 since the islands were discovered. Pleas were among the early arrivals, and 

 may be said to abound in certain localities, especially dry elevated places. The 

 native name (Ukulele) for a "jumping louse" was early applied to this 

 tormenter, which is one of the few insects it is not necessary to see in order 

 to identify. "While they occur about houses and bite the inmates and their 

 pets, the species most commonly captured are the cat-flea or the dog-flea, *■* 

 though the comon human species*"' doubtless occurs. 



Plague Carried by Fleas. 



One of the many brilliant medical achievements for which the closing 

 years of the last century were especially noted, was the discovery that the flea 

 that lives on the common rat is responsible for the spread of the dread bubonic 

 or black plague. It has been proved over and over again that rats die of this 

 disease and that the fleas which infest them and feed on their blood draw the 

 minute organism causing the disease into their bodies in such a way that they 

 can communicate the plague to other rats and to other animals, among them 

 man, by their bite. Cases are on record where death from plague has been 

 traced to its origin only to find that it came from flea bites. Fleas usually 

 leave the carcass of a rat that has died of plague and at the first opportunity 

 take \\\) their abode on some living animal, as the cat or dog. Prom these pets 

 they are easily transferred to their masters, with the result that their bite may 

 convey the minute microscopic organism *" that causes plague in the human 

 body. Plague has appeared on more than one occasion in Hawaii,**" and to all 

 appearances has been successfully siniiipcd out. Xevertheless, it is well for 



"^s Oribatid(t. "® Oribata oriformis. so ^feoUodea theUproctus. si Rhipirephalus savf/idneiis. 



S2 Tetranyrhus sp. ss Sarcoptes scahei. s* Ctenocephalus cavis = Pulex caniti. sc Pul^'x irritnns. 



s^ Bacilua pestes. 87 Notably during the wmter of 1900. 



