10 THE ZOOLOGIST. 
To the field ornithologist who prefers labelling his specimens 
ipse, there is much to disappoint in Valkenswaard, and the boys, 
who, at the end of one of the numerous saints-days and holidays, 
bring their hatfuls of eggs of Orioles, Water Rails, Spotted Crakes, 
and Black Terns, afford but little satisfaction in reply to enquiries 
concerning unidentified possible rarities. 
One ought really, at a place like this, to set one’s face against 
any payment for eggs, unless they can be shewn in situ. The 
pleasure to be derived from taking with one’s own hands a single 
clutch is far greater than that which emanates from the 
possessing of some score of eggs of whose history nothing is 
known. At the end of a fortnight, within a reasonable distance 
of the village, we found only empty nests and reed-beds trampled 
through, and our only chance of success was to take a long walk 
straight away from our quarters, or travel a few stations farther 
on the line and work back again. 
The Black Tern, Hydrochelidon nigra, was one of the most 
interesting species we met with, and its graceful evolutions en- 
livened many an evening’s walk over the marshy moor, as we 
returned tired and fagged after a long day. At this time, when 
their mates were sitting, it was very amusing to watch them take 
the Field Crickets, Acheta campestris, as they came to the mouths 
of their holes for a little fresh air. These were exceedingly 
numerous, their chirrupings forming a continuous refrain, and 
were evidently a favorite food supply for the Terns. Great 
quickness is necessary to catch them, as they never move far 
from their holes, and pop in on the slightest alarm, but very few 
evaded the swift stoop of the bird. The first fresh eggs of this — 
species were taken on May 21st, and numbers had begun to sit by 
June 3rd. Nearly all the nests had three eggs, but a few were 
found with only two. We were lucky in discovering several large 
breeding-places which the boys could not reach, and thus had ample 
scope for observation. These places were large pools of standing 
water on the open heath, with boggy bits of island here and there, 
and heaps of wrack kept steady by the water-grasses; a few bits 
of grass were collected together, and the eggs laid on them. In 
such situations they were high and dry, but one nest in a running 
stream (the only one found so) was wet through, floating partly on 
the surface; it was composed of a considerable quantity of water- 
plants, and was kept steady by some rushes bent down. Our 
