CUCULUS CANORUS L. 



greatest latitudinal diameter intersect one another, which point is 

 always nearer the thicker end, whilst the curve at the pointed end 

 is not so round as is the case with most Oscines-eggs. 



When determining, attention should be paid especially to the 

 characteristics enumerated under 2, 3, and 4. 



Link x ) gives the following explanation of the phenomenon that 

 the weight of the canon/s-eggshell is so great in proportion to its 

 comparatively small size and its thinness: „When the shell is being 

 „formed the particles of lime adhere together during the process of 

 „settling and crystallization more compactly than in other eggs; a 

 „natural result of this circumstance is the marked firmness and the 

 „great specific weight of the canon/s-eggshell, without this shell 

 „being positively thick". 



Link is not the first to express himself in this sense. Nine years 

 previously Capek a ) who, strange to say, is not quoted at all by 

 Link, wrote: „Die Festigkeit der Schale ist ein sehr wichtiges 

 „Criterium der Kuckuckseier; ihre Ursache haben wir in der com- 

 „pacten Masse der Schale zu suchen. Gewiss ist der Umstand dass 

 „ Kuckuckseier urspriinglich naturgemass grosser waren, die eigent- 

 ,licke Ursache dieser merkwiirdigen Textur der Schale; die Eier 

 „verkleinerten sich, aber das Quantum der Kalkmasse ist verhaltnis- 

 „massig gross geblieben, wodurch die Schale compacter wurde." 



As regards the number of eggs which one canorus-iema.\e bird 

 lays in a season, Link 3 ) has, as a result of his many years of 



2 ) Verhandl. d. Ornith. Ges. in Bayern, VI (1905). Munchen, 1906. 



2 ) Ornith. Jahrbuch, VII. Hallein, 1896. 



3 ) 1. c, IV (1903). 



