THE EGGS OF BUTTERFLIES. jgi 



so as better to l)e described as spindle-shaped, and it is nearly always 

 broader at the base than at the siuninit, so as to merit the term pyramidal, 

 sometimes much broader, as in Speyeria. The ti-uncate top is also very 

 frequently rounded and its edf^c inconspicuous, and it then runs into the 

 si)herical or iiemispherical class ; luit the true barrel-shaped group is always 

 higher than broad. The Nymphalidae and Pierinae almost always belono- 

 to this group, and they are always vertically ribbed to some extent, but the 

 ribs always terminate short of the centre of the summit, either gently or 

 abruptly. Sometimes these ribs are coarse and irreg-ular, runnino- in zio-- 

 zag lines from base to summit, so that the egg might almost be regarded 

 as coarsely reticulate ; in others the ribs are excessively compressed, mere 

 films, placed edgewise to the body of the egg, glistening in the sunshine 

 like dew-drops, and increasing in size to the summit, where they often form 

 a sort of crown ; or they may die out on the lower half of the egg, or fade 

 into a weaker reticulation ; or, above, may terminate at the edge of a 

 saucer-like depression which forms the cap of the egg ; but everywhere, 

 with more or less distinctness, between these buttressing ribs, the surface 

 of the egg is broken into quadrangular cells by delicate cross-ridges, which 

 often increase in stoutness toward the main ribs, and in their turn buttress 

 them. 



The spherical forms include particularly the Papilioninae, some Saty- 

 rinae and the Hesperidi, unless these last more properly belong to the 

 preceding group. They are usually smooth, but may also be reticulated 

 or, as always in the Hesperidi, ribbed. 



The tiarate eggs are very beautiful objects, often reminding one of a 

 miniature sea-urchin without spines, and are characteristic of the Lycaeni- 

 dae, though some of them incline toward the hemisperical form, and all, 

 without exception, are reticulate. In these the surface is never ribbed, 

 but generally covered with a heavy net-Avork of deep pits, whose bounding 

 walls are rather coarse and rough. The eggs of the Parnassians resemble 

 them closely. 



Finally the hemispherical eggs, generally more than half as high as 

 broad, and with a slight flattened summit, are smooth and comprise only 

 the Pamphilidi, if we except the reticulated Heodes, which possibly belongs 

 here as much as with the turban-shaped eggs. 



As an architectural form, the egg of a buttei-fly is exquisitely patterned. 

 AVith all the variation in sculpture and contour, every curve and every 

 detail of chiselling is in subordination to a central feature — all lead up to 

 a distinct culminating area, the micropyle, or little rosette of cells of the 

 most exquisite delicacy, which crowns the summit of the central vertical 

 axis. Often requiring some of the higher powders of the microscope to 

 discern, the cells are arranged in such definite and regular patterns that in 

 looking at them we seem to be peering through the circular rose-window 



