302 Bulletin of the British Ornithologists^ Club. 



publications in Geroiany wlncli appear to be not generally 

 known in this country. 



" The first is a book of 108 pages by Dr. E. Key, ' Altes 

 nnd iSTeues aus dem Haushalte des Kuckucks.'' This book 

 may be known to many British ornithologists by name, but 

 I have seen no comment on the surprising statement that the 

 old theory of the slow development of the eggs in the ovary of 

 the Cuckoo is erroneous, and that the Cuckoo lays its eggs at 

 much shorter intervals than is usually supposed ; and, further, 

 that it lays from seventeen to tioenty-two eggs. 



" I will only add that the statements of Dr. Rey are based 

 upon an immense mass of material, probably greater than 

 has ever been examined by a single naturalist, and that his 

 results are founded upon a long experience. I myself can 

 make no comment, and I need hardly add that there are 

 several other interesting questions treated of at length in 

 Dr. Key's book. 



" The second publication to Avhich I wish to draw atten- 

 tion is a pamphlet of 64 pages, by Dr. Heinrich Wickmann, 

 ' Die Entstehung der Farbung der Vogeleier/ It treats of 

 the origin of the coloration of eggs. This interesting 

 question is difficult to solve, and very little is yet known 

 about it. 



" The only positive result that has come to light from prac- 

 tical investigations on fresh birds with regard to the ques- 

 tion, — ' where in the body of the bird dues the colour of the egg- 

 shell originate,' seems to have been Dr. Kutter's observation 

 on an egg found in a female Falco tinnunculus. Kutter's 

 observations led him to believe that the colour originated 

 in the upper part of the oviduct, and this was generally 

 accepted, as no other theory seemed to rest on any assured 

 basis. Now, however. Dr. Wickmann, after a period of some 

 years' careful studies and numerous dissections of birds, 

 comes to the conclusion that the colour originates even 

 earlier than in the oviduct, i. e. in the ovary itself I 



"The pamphlet must be studied before being criticised, 

 and I can only add that Wickmann's deductions seem to 

 be very clear and convincing ; but I hope to find leisure- 



