156 A. C. OUDEMANS. ACARI. 



popular term' for the lésions proceeded is scrub itch. — The tick does not, however, seem to 

 be of universal distribution at least at the same time of the year. — Besides suffering from it 

 in British New Guinea proper, 1 can testify to its prevalence and virulence on Murua (Wood- 

 lark Island) off the S. E. extremity of British New Guinea." 



The supposition of SELIGMANN that the occurrence of the mite may be dépendent 

 from the time of the year may be probable, as in Europe the occurrence of the harvest- 

 mite is also bound to a few months ; but in tropical régions it is more probable that the 

 larvae occur throughout the whole year. 



Hère I am at the end of the history of the New Guinea mite, and I could finish, but 

 I think it is better to add hère what Mr. YAN DER Sande has found about similar plagues 

 in Ceram and Celebes. 



The oldest informations about the Ceram harvest-mite are from the well known ALFRED 

 RUSSELL WALLACE. 



In his famous work The Malay Arclùpelago : the land of the Orang-Utan and the bird 

 of Paradise, 1869, v. II, p. 46, we read : 



„A11 the time I had been in Ceram I had suffered much from the irritating bites of 

 an invisible acarus, which is worse than mosquitoes, ants and every other pest, because it 

 is impossible to guard against them. This last journey in the forest left me covered from 

 head to foot with infiamed lumps, which after my return to Amboyna, produced a serious 

 disease, confining me to the house for nearly two months, — a not very pleasant mémento 

 of my first visit to Ceram — , which terminated with the year 1859." 



WALLACE seems to hâve immediately recognized the nature of the créature as being 

 an acarus. Why then does he call them „invisible", why does he not say „almost invisible"? 



The trips or expéditions of WALLACE in Ceram took place in the rain-season, and 

 the country is described as „one dense, unbroken, and very damp and gloomy virgin forest"; 

 he was often obliged to ford little rivers, of which the water sometimes reached till above 

 his waist, and to pass the night in primitive bivouacs in the forest. The bad condition too 

 of his shoeing must hâve made easy to the mites to reach the naked skin. WaLLACE writes 

 hereof on p. 45 : 



„The constant walking in water, and over rocks and pebbles, quite destroyed the two 

 pair of shoes I brought with me, so that, on my return, they actually fell to pièces, and the 

 last day I had to walk in my stockings very painfully, and reached home quite lame." 



Follow the expériences of K. MARTIN. On p. 144 of his Reisen in den Molnkken, in 

 Ambon, den Uliassern, Seran {Ceram) und Burn. Eine Schilderung von Land nnd Leuten ; Leiden, 

 1894, he writes: 



„Angriffe von sehr kleinen Milben oder Holzbocken, denen man in den Wàldern fort- 

 wàhrend ausgesetzt ist, sind schon allein geniigend, die unreinen Wunden hervorzurufen, deren 

 Heilung durch den ausserordentlichen Schmutz der Alfuren selbstredend nicht befôrdert wird. 

 Auch mein eigener Kôrper war nach làngeren Reisen im Innern der Insein stets mit Wunden, 

 die von derartigen Thieren herrùhrten, bedeckt ; es bildeten sich oft dicke Geschwure, welche 

 nach dem Abfallen rothe Flecken in solcher Zahl zurùckliessen, dass meine Beine durch dièse 



