REED-WARBLER. 873 
we found no nests and saw no birds. The nests were very easy to find. 
Some were long and tapering ; but most had little or no unnecessary foun- 
dation. There were generally three or four reeds interwoven into the 
sides of each nest. Swaysland had an idea that the nests were so built 
that they could rise or fall with the rise or fall of the water; but we found 
that most had a leaf projecting close to the nest both immediately above 
and below the nest on one or other of the reeds, which would make any 
movement of the kind impossible. 
There was frequently a little wool or thistle-down used in the construc- 
_ tion of the nest ; but dry grass-stalks and roots were the principal materials. 
Ten days later there would no doubt have been plenty of eggs; but we were 
afraid that we were too late already. Possibly the cold weather may have 
been the cause of the delay; or it may perhaps be accounted for on the 
theory that Swaysland caught most of the original settlers on this dyke, 
and that the birds we saw were a later arrival of Reed-Warblers which 
had been driven out of the adjoming dykes by their quarrelsome neigh- 
bours. The eggs of the Reed-Warbler vary from *78 to ‘7 inch in length, 
and from ‘55 to *5 inch in breadth, and are from three to five in number. 
Dixon writes, “‘It is worthy of remark how very distinct generically the 
eggs of the British Warblers are. The eggs in each genus, almost without 
exception, are peculiar. ‘Thus in the Willow-Warblers (Phylloscopus) we 
have pure white eggs spotted with red; in the Tree-Warblers (Hypolais) 
the eggs are salmon-coloured spotted with purplish brown; in the Grass- 
hopper Warblers (Locustel/a) the finely powdered markings of brown and 
their general pinky appearance are characteristic of them alone ; whilst in 
the Reed- Warblers (Acrocephalus) greens and olive-browns are the predo- 
minant colours. In the true Warblers (Sylvia), however, there is not so 
much uniformity ; and this circumstance doubtless to some extent proves 
the greater antiquity of these birds as compared with the birds of allied 
genera. It seems to me that the very distinct variations in the eggs of 
the true Warblers show a wide differentiation of many of the species ; but 
in the allied groups (Acrocephalus, Locusiella, Hypolais, Phylloscopus), 
although the species have become fairly differentiated, the eggs have not 
yet had time to vary, and consequently a certain type of egg runs through 
each respective genus. What part these variations play in the economy of 
the birds still remains to be discovered ; but I think it is very clear that 
these well marked generic types of eggs prove a not very remote evolution 
of the birds in each of these genera severally from a common parent.” 
The general colour of the upper parts of the Reed-Warbler is olive- 
brown suffused with rufous, especially on the rump and upper tail-coverts. 
The eye-stripe is nearly obsolete; and the innermost secondaries have 
broad ill-defined pale edges ; the breast, flanks, and under tail-coverts are 
rufous-buff, shading into nearly white on the chin, throat, and centre of 
