A. C. OUDEMANS. ACARI. 159 



are abundant in coast parts with black sand, like at Andai, a little more southward. In the 

 Xumfore dialect the mite is called arkan." 



„Our expédition has experienced the présence of the bushmite on ail its trips, also in the 

 country inhabited by the tribe of the Manikion and which lies exactly on the north of the 

 Maccluer Bay, consequently not far froin the parts where VAN DlSSEL traveled." 



»The minute dimensions of the mites hâve thrown considérable obstacles in the way 

 of finding thèse organisms, and this sufficiently déclares why several able gentlemen, amongst 

 whom there are zoologists, came to inexact inferences about the real nature and biology of 

 the créatures. With respect to this, LAUTERBACH says that the mites dig or burrow themselves 

 in the skin ; the cousins SARASIN that they dig themselves in the pores of the skin and bed 

 themselves therein, but die hère; Prof. WlCHMANN that they burrow themselves in the skin, 

 lay hère their eggs, and that their larvae give rise to the origin of blisters." 



.Adjoining my own expériences, I am obliged to suppose that the mites remain on 

 the surface of the skin and only put their mouth parts or mandibles in it. This I infer from 

 the fact that the mites collected by me, indifferently either they were collected shorter or 

 longer after the beginning of a trip, could be struck off with a little knife going with it 

 exactly over the surface of the skin, not damaging them otherwise than on the mouthparts. 

 Thus the body itself of the mite projected always out of the skin. I hâve never observed 

 that they clinged to the hairs or looked especially for the outlets of the sebaceous glands." 



.The symptoms which the mites excite in men, I suppose, are exclusively brought about 

 by the poisonous spittle run in the wounds. In one person thèse symptoms are less or more 

 intense; this, I suppose, is the resuit of the quantity of poison, thus of the duration of the 

 stay of the mite on the skin. Différent individuals moreover react very differently on this 

 agency. One of the Europeans of the six under my observation, perceived subjectively not 

 more than a light tickling, which even not always gave rise to scratching, whilst objectively 

 only light red coloured and little raised blisters of little extent (2 to 3 millimeter in diameter) 

 could be observed. It was only on this person that I succeeded in finding the mites, because 

 thèse had not been removed by scratching." 



„As well the subjective as the objective symptoms now may increase in intensity, 

 without that hère exists any parallelism. The tickling may increase to an insufferable itch, 

 so that the patient scratches the corium to pièces, by which the mites of course are removed 

 and whereupon the itch for the greater part disappears." 



,The blisters may increase to become vesicles and bullae, wholly filled with a serous 

 liquid, and having a diameter of about 3 centimeter and a height of about 8 millimeter. I 

 hâve never observed the mite on thèse bullae, nor on the wound bottom of it, when the 

 bullae and the serous fluid had been removed. I happened to see very large bullae in a case 

 wherein the patient had not experienced intence itching. When, however, intence itching 

 takes place, nobody can withstand the temptation to scratch the skin to pièces, whereupon 

 of course the arising of bullae is anatomically not more possible. Thèse wounds are a. o. 

 particularly characterized, that, evidently in conséquence of the spécifie poison, they at first 

 do not show any tendency to healing, on the contrary the skin swells, and along the edges 

 there arises a zone of increasing redness and infiltration. After the highest stade the skin 

 régénérâtes for the greater part from the circumference to the centre, and is characterized 



