LIFE-HISTOKIES. 53 



any way to the sac, but moved freely in it. In one case, the second, 

 the 5 netted by me was actually flying with the ovum already in her 

 sac. Can it be that the female oviposits into her sac while on the flower- 

 tops, and afterwards proceeds to deposit the egg at the foot of the 

 foodplant? Can anyone oft'er a more satisfactory explanation? — P. A. 

 H. MuscHAMP, 20, Chemin des Asters, Geneva, Decetiiher 20th, 1903. 



Egg of Spilosoma mendica compared with that of Phragmatobia 

 FULiGiNosA. — To the naked eye the egg of Sjnlosoiiia mendica appears 

 to be a larger egg than that of P/ua;iiiiatnbia fidi(/i)iosa. The eggs 

 examined were laid on the sides of a glass-topped box in smaller and 

 more regularly-sized patches than those of the latter species, in 

 two instances a couple of eggs are laid singly a little distance 

 apart from each other. The smallest regular patch contains 34 

 eggs, the largest 52, there are three other patches, which avertige 

 about 40 ova each, the total number of eggs being about 

 200 to 220. They are not nearly so near hatching in appearance 

 as those of P. fnluiinom, their colour being a pearly cream, very 

 similar to the latest-laid ova of P. fidit/inosa in this respect. The 

 shape is less spherical than that of the egg of P. fttlininosa, and shows 

 a tendency to become a tall dome, the vertical axis being larger in 

 relation to the hoiizontal one, the base flatter and less depressed. 

 Horizontal diameter is about •75mm., vertical, almost exactly the same, 

 perhaps a trifle less, -Tmm. to -TSmm. Surface smooth and shiny 

 with a pearly lustre, the surface reticulation quite as faint, and less 

 sharp, but clearer at the micropyle than that of P. fnluiinosa. When 

 placed on a glass slip together, the difierence is abundantly distinct, 

 the greater bulk of the egg of S. mendica being at once apparent. The 

 cellular reticulations are also very different in the two ova, that of P. 

 fnlif/inosa being very much sharper and smaller, and is clearly a surface 

 structure, that of S. niendica is larger and consists of indentations 

 rather than a network of walls, giving more the effect of the dents left 

 by the hammer in beaten copper work. The eggs commenced to hatch 

 three or four days later than those of P. fidiciinom. [Eggs of .S'. 

 mendica received from Mr. Tutt, April 20th, 1903, laid April 11th 

 and following days, by a $ caught flying in the Esterel, at Agay, on 

 the mornmg of April 11th, 1903.]— A. W. Bacot, F.E.S., 154, 

 Lower Clapton Road, N.E. November 18th, 1903. 



Eggs of Lepidoptera. — FAlopiafasciaria var. prasinaria. — When first 

 laid the egg looked at from above is roughly oval (inclining sometimes to 

 circular) in outline, full and plump, without depressions of any kind, 

 flattened at the )uicropylar end, which is fuller and broader than its 

 nadir. The egg is green in colour, the surface somewhat shiny, and 

 with the power at disposal appears to be minutely granulated or pitted, 

 although, to the naked eye, it seems quite smooth. The length : breadth 

 : thickness as about 9 : 7 : 6 at the micropylar end, the nadir of which 

 is only about two-thirds of this in thickness. This description was 

 made on August 20th, 1903, from a single egg laid by a $ captured 

 on the evening of August 18th at light at Chamonix. On the evening 

 of the 21st it was observed to be changing to a red colour, whilst on 

 the 22nd another J (which had been isolated for eggs) was observed 

 to have laid several eggs in the box in which she was confined. 

 Other eggs were laid on the 23rd, the $ dying during the night. 

 On the 25th these eggs were carefully examined, when the following 



