26o 



NATURE 



[April 28, 192 1 



the beak is just meeting the water to complete 

 the downward half of the semicircle which he 

 describes." 



How different from the submergence method 

 seen in the true divers ! One cannot but admire 

 a picture like this. The Manx shearwaters sleep 

 in their burrows by day, and start out on their 

 labours as dusk begins to gather. 



"They have a curiously silent flight, gliding 

 past one in the gathering gloom like ghosts 

 indeed. I know no bird, except perhaps some 

 of the owls, whose flight is so absolutely noise- 

 less. The effect is curiously uncanny ; they appear 

 suddenly out of the darkness and disappear again 

 like spirits of another world." 



Dr. Ogilvie's study Qf the grey partridge 

 affords an interesting illustration of our relative 

 ignorance of a very common bird. In cold, frosty 

 weather the partridges huddle up closely at night, 

 "shoulder to shoulder, forming a circle with their 

 tails in the centre " ; yet J. G. Millais writes to 

 the editor to say that the "jugging" birds he has 

 seen had their heads directed inwards. " During 

 the period of incubation, the scent is suppressed 

 entirely, or so little is left that you may take a 

 first-rate dog within a foot of a sitting bird over 

 and over again, and he will not evince the smallest 

 interest in the locality." But does anyone know 

 precisely how this life-saving suppression of scent 

 is effected ? When suddenly threatened with 

 danger the parent partridges utter the warning 

 cry, and the chicks 



"squat flat upon the ground, as if they were 

 trying to squeeze themselves into the very earth 

 itself, with nothing to show the presence of life 

 but their little black, beady eyes. As long as the 

 danger remains imminent, the parents keep up 

 an incessant chuck-chucking, and the chicks re- 

 main absolutely still and motionless. This instinct 

 in itself is very curious, for it is evidently inborn. 

 A chick that is only two or three hours old will 

 ' squat ' at the warning cry, with the same 

 celerity and certainty as a chick of three or four 

 weeks. It can be no question of learning by ex- 

 perience and parental training. It will squat at 

 that cry, and at that cry only, though not from 

 any knowledge of the safety so acquired. Part- 

 ridges reared under a hen never squat, although 

 danger is threatening, and the foster mother is 

 clucking in a dreadful fluster. . . . The necessary 

 stimulus is absent, and that stimulus is supplied 

 by one particular cry of the parents and nothing 

 else." 



Except for the sentence : "This instinct in itself 

 is very curious, for it is evidently inborn," this 

 record of observations is admirable, and the whole 

 account of partridges gives the reader a clear 

 impression of the author's grip and carefulness. 



In regard to the snipe's "drumming," there is 

 NO. 2687, VOL. 107] 



a fair-minded discussion of the four theories, the 

 author holding firmly that the rapidly beating 

 wings, whether they themselves hum or not, - 

 throw a strong current of air on to the outermost 

 feathers of the tail, setting them in vibration 

 which produces sound-waves. As to the position 

 of the orbits, 



"a snipe, with its eyes placed as they are, can 

 get the very last fraction out of its bill, as it- 

 struggles for a worm half an inch further down 

 in the mud, and yet see all that is going on 

 round it, and be ready for any emergency that 

 the fates have in store." 



The cry of the stone curlew is 



"a weird discordant clamour, with something 

 uncanny and blood-curdling about it, as though 

 an inferno had suddenly been let loose on earth. 

 We call them ' shriek owls ' on this account, and 

 it is not a bad name. Their wild cries ringing 

 out loud and clear, then suddenly ceasing and 

 intensifying the silence of the still summer night, 

 are something suggestive of murder and sudden 

 death." 



Regarding the much-discussed serrated claw of 

 the nightjar (also found in the bittern, gannet, 

 heron, and courser), Dr. Ogilvie suggested that 

 it was "a vestigial remnant from some bygone 

 ancestor, which has long since lost its original 

 function, and is now, perhaps, of little service tO' 

 these latter-day descendants." The editor, whose 

 notes form a valuable addition to his friend's 

 book, remarks that an objection to this theory 

 is to be found in the fact that the pectination is' 

 not found in the nestling, but develops later, an 

 unusual feature of vestigial structures. 



The rhythmical movements of the cuckoo's; 

 stomach during digestion press the hairs of the 

 hairy caterpillars against particular areas of tlie 

 mucous wall and embed them in the epithelium. 

 Are they shed after a time? Are they ejected as 

 pellets? Do they impede digestion? Are they 

 responsible for a large mortality among the im- 

 mature cuckoos? These are interesting questions 

 which the author raises, but he need not have 

 asked : " Do the implanted hairs actually take 

 root and grow in their new situation? " Never- 

 theless, particular attention is paid to the food 

 of certain birds, and there is much information 

 on the subject in his book; thus he maintains 

 that the sparrow-hawk is not so black as it is 

 painted, nor the kestrel so innocent. 



Dr. Ogilvie was a sportsman-naturalist, and 

 the sportsman's interests are prominent in these 

 pages, but, on the whole, they are kept in sub- 

 jettion to the interests of ornithology, and the 

 result is what wp venture to call a very happy, as 

 well as a very scientific, book. 



