HOLMESDALB NATURAI, HISTORV CLUB. 13 



colored eggs It has been ascertained by means of the spectrum 

 that seven well-marked substances enter into the composition of the 

 coloring niatter of the shells of eggs, and that the various shades 

 of color observable m different eggs are all due to the presence of 

 one or more of these pigments in various proportions. The red is 

 found to be derived from blood-secretions, and the blue and yellow 

 from bile-secretions. The grain of the shell varies very greatly 

 from the rough surface of the egg of the Emeu, or the chalky ess 

 of the Cormorant, to the wonderfully smooth and glossy surface of 

 the egg of the Tinamou. The shape is equally various, from the 

 almost spherical eggs of the Owls and other birds of prey to the 

 long eggs pointed at both ends laid by the Grebes, or the pyriform 

 eggs of many of the Waders. Owing to this pyriform shape the 

 bird IS able to cover much larger eggs than would be the case if thev 

 were oval, as the four eggs when placed with the points together 

 occupy a mimmum of space. In connection with this it must be noted 

 that the young of most of these species begin to run almost as soon 

 as they are hatched, and are consequently more fully developed at 

 their birth than many other birds. There also seems to be some 

 relation between the number of eggs to be covered, and their size: 

 thus the egg of the Snipe is about the same size as that of the 

 Partridge, the bird itself being far smaller; but the Snipe invariably 

 lays four eggs, while the Partridge often lays twelve or more. AgaiJ 

 the Guillemot which lays only one egg, is a bird about the sime 

 size as the Raven yet in the size of their eggs there is a very wide 

 diHerence, the Guillemot's being many times the larger. 



Evening Meeting, April I3th, 1877. The subject of " Pond 

 Lile was considered, being introduced by a paper read by Mr H 

 h. Lox on the Coleoptera of ponds. These might conveniently be' 

 arranged m three divisions, according to their mode of life viz 

 1st. i hose found in or on the water itself. 2nd. Those found iii 

 the banks of the pond, or in marshy ground at the margin of the 

 water. 3rd. Those found in or among aquatic plants. Mr. Cox 

 then described the structure of the first of these groups, showing 

 how admirably it is adapted to enable them to live in and movi 

 through the water ; and explained the mode in which the oar-like 

 legs act as propellers, and also the provision for breathing beneath 

 the water. Under this group he alluded especially to the Dytiscid^ 

 and Gyrmidae, and then touched upon the most noticeable points 



R^S? ■? \°. i!' ^'^^ S.'^'^P'- Speaking generally of ajuatic 

 Bee les, it might be said that those which swim in water are of a 

 black or dark brown color ; those found on plants under water are 

 lightish brown often with iridescent reflection; and those found 

 on the leaves of plants above the water are brightly metaUic. 



