CHARADRIIDAE — SCOLOPACIDAE. 



ciious, oologically too, and in this connection to draw attention more 

 particularly to the genera Lams, Sterna and Hydrochelidon of these 

 Families. 



VANELLUS VANELLUS (L). 



As regards the so-called , mimicry" of vanellus-eggs, namely the 

 resemblance of their ground colour to that of the soil on which 

 they are laid, it should be observed that quite as many cases occur 

 in which this resemblance does not exist as in which it does exist 

 more or less; at any rate a general and constant phenomenon in 

 the above sense cannot be said to exist. 



That the difference in colour and spots is connected either with 

 the age of the female birds (the eggs of old female birds are said 

 to be of a darker tint and to show larger, frequently confluent, spots 

 than those of young female birds) or with the food offering in their 

 vicinity, and with tJie time when the eggs are laid, has still to be 

 effectively confirmed by scientific investigation and experiments. ') 



Even if the influence of the food is assumed a priori as certain, 

 the question, amongst others, as to whether a particular kind oj 

 food causes a particular colour and marking or whether only a 

 more or less plentiful nourishment has a governing effect, still remains 

 unanswered. 



if the vanellus-clutches found towards the end of A pril are darker 

 on the whole than those found in the latter part of March (cf. what 

 is said respecting Charadrius apricarius), the quantity as well as 



') The discolouration of the eggshell obtained artificially (namely by means 

 of unnatural food) in the case of Fringillidac kept in confinement, can, in my 

 opinion, scarcely obtain as an in every respect decisive result where the 

 question here involved is the influence of natural food on the pigmentation 

 of the eggshell in the case of wj'M birds. 



