PRESERVATION OF DESMIBS. 19 



and a little practice soon enables one to estimate about tbe rigbt 

 amount. In connection with this method of filtering in the field 

 I have one more accessory to mention which may appear trivial 

 to those unaccustomed to moorland collecting. This takes the 

 form of a light wand about 6 feet in length, which is stuck in the 

 bushes containing the filters ; a hazel stem cut from the hedge- 

 row on the way answers every purpose. The object is to enable 

 one to find the filters readily when collecting operations lead one 

 unconsciously some distance away. It may appear unnecessary, 

 and I do not insist on it ; but one morning on Dartmoor when 

 working a somewhat extensive bog it took me an hour's diligent 

 searching to find the heather bush containing my filters, which 

 were eventually found on quite the opposite side of the bog from 

 the one about which I had been searching. Several collecting 

 articles I have never found, owing largely to the similarity in 

 appearance among heather bushes when dotted about extensive 

 moors. 



As regards the results obtained by the collecting method just 

 described, when I state that from about 10 c.c. of material taken 

 from one small unimportant bog I obtained over one hundred 

 species and varieties it will be seen that it is a very practical and 

 productive method. From large, old-established bogs the result 

 in individuals and species is really very remarkable, and from the 

 collections made during a summer excursion on the north-eastern 

 part of Dartmoor I have obtained four hundred species and 

 varieties, and have still a large quantity of material remaining 

 unexamined. For the benefit of those unaccustomed to moor- 

 land collecting a warning may be given as to the character of the 

 bog. If a collecting excursion were made to a moor like Dart- 

 moor in late spring or early summer a good deal of disappoint- 

 ment might be experienced from working impermanent bogs. 

 These form during the winter seasons, and as summer advances 

 dry up. The collecting in them is seldom remunerative. It is 

 the old, deep and permanent bogs that yield the best collections^ 

 and one of the tests that I apply to a bog is the presence or absence 

 of Sphagnum cuspidatum, this species rarely occurring in any but 

 permanent bogs. Moorland pools are always w^orth the col- 

 lector's attention, and often yield quite different species from 



