20 



The nests were placed in the bank of a disused pit, and the soil consisted of clay, mixed 

 with sand and small pebbles. Tunnel no. 1 was 2 feet long. Tunnels nos. 2 and 3 ran 

 into a common passage 2 feet 8 inches long. Nos. 4 and 6 were each 2 feet 4 inches 

 lono-. No. 5 was abandoned, the presence of a large stone preventing the bird from 

 completing it. No. 8 was 2 feet 7 inches long, and nos. 7 and 9 were 3 feet 3 inches in 



length. 



In the ' Birds of North America,' by Messrs. Baird, Brewer, and Ridgway, occurs 



the following note : — 



" Mr. Augustus Powler mentions a remarkable instance of sagacity and provident 

 forethought in these birds, not easily separable from reason. In the town of Beverly, in 

 a stratum of sandy loam, he observed each season a colony of some tw^enty or thirty pairs 

 of these birds. In this place these birds never burrowed more than two or three feet. 

 "Within a mile of this place another colony excavated a bank in which the layer of loam 

 was mixed with small stones. In this bank they excavated to the depth of five, seven, 

 and even nine feet. Why was there this extraordinary difference in the length of 

 burrows made by the same species, in situations not more than a mile apart ? The 

 reason for this difference, upon examination, became very obvious. We give the expla- 

 nation in Mr. Powler's own words : — ' In one bank, where the earth was of a fine sandy 

 loam, easily perforated, from the entrance to the extremity the burrows did not exceed 

 three feet in length ; while in the other bank, with harder loam to work in, one burrow 

 was found nine feet in length. After examining sis holes of nearly equal length, it 

 appeared that these little birds had sufficient reason for extending their labours so far 

 into the earth. In every instance where they met with a sj)ot free from stones they 

 finished their burrows ; thus showing great care for the welfare of their eggs or young, 

 by avoiding, in the stony soil, a catastrophe so great as would befall their treasures if by 

 accident one of these stones should fall upon them.' " 



As noticed by Dr. Taczanowski above, the situation of the Sand-Martin's nest in the 

 low banks of rivers sometimes exposes the bird to the risk of destruction by floods ; but 

 an unexplained cause of the death of some of these little birds is given by Mr. Treat in 

 the 'Auk,' for 1890 (p. 9G) :— 



" I made a trip to a place where hundreds of these birds breed every year. I saw 

 no birds about the holes, and at once concluded that the birds had not bred there 

 that year, but as the holes seemed to have been excavated recently, I examined them, and 

 found dead birds in nearly every hole I dug into. Some of the birds were quite fresh, 

 while others had the appearance of having been dead a long time. These birds were 

 not in very good condition, but were far from being poor and emaciated. Almost all 

 the holes contained nests, but very few had eggs in them, and two were the most I found 

 in any one nest. As to the cause of their destruction I am w'holly perplexed." 



The Plate represents an adult and an immature bird from specimens in Mr. Wyatt's 

 collection, and the descriptions are reproduced from tlie British Museum ' Catalogue of 

 Birds.' 



Eor the range of the present species, vide infra, Plate 30 [Map]. 



