( Ivi ) 



since I am to remain here another season, I wish, by fiUing 

 up all gaps, to make the collection practically complete, that 

 is, so nearly complete that it will give a definite idea of the 

 fauna, with the proportionate representation of all the families. 

 It seems to me that the cause of science will be better served 

 by such a complete view than by any number of new species, 

 and one island thoroughly worked up in this way will serve 

 as a basis for comparison with all the others. The micro- 

 scopic infusoria, &c., are of course out of the question, as they 

 must be studied in the field by a specialist. But, beyond 

 these, there are many things of more or less difficulty in 

 preservation which I should like advice about. 



" 1. Planarians, slugs, and earthworms. — These are few, 

 but ought to be noticed. Alcoholic specimens can hardly be 

 studied ; is there no means of preserving them ? 



*' 2. Internal parasites of birds, &c. — There are some curious 

 ones also in insects, especially grasshoppers. 



*• 8. Mites. — The larger ones can be preserved in alcohol 

 very well, but there are numerous very minute ones ; should 

 these be mounted in balsam ? Of course a full collection of 

 mites is out of the question, but I might get a good repre- 

 sentation. 



" 4. Thysanura, Poduridfe, &c. — I have preserved a few in 

 alcohol, and they seem to do very well, but others would be 

 likely to lose their scales. Sir John Lubbock would doubtless 

 give you information on this point. The forms are quite 

 numerous, and would be of especial interest. 



" 5. May-flies. — I have seen no large forms here, but quite 

 a number of small ones. They shrivel more or less, and to 

 some extent lose their colours in drying ; shall I put them in 

 alcohol ? 



" 6. The winged forms are not very numerous, and I have 

 dried a few successfully ; the wingless forms, I suppose, can 

 be preserved in alcohol, if we could tell the larvfe from adults. 



"7. Aphidce. — There are a few species; I can dry the 

 winged forms ; shall I put the wingless ones in alcohol ? 



" 8. Cocciihc. — I can get the scales easily enough, but will 

 these be enough to determine the species ? 



" 9. Very delicate flies, as Cecidomijidce. — The only trouble 



