SESIA STELLATARUM. 7 



egg, if laid on a bud, is, of course, turned downwards, and the petals, 

 though small, hide the egg ; when the plant is in full bloom one 

 might suppose that the egg had been deposited in the centre of 

 the flower-head which, however, is not the case ; if a plant be in 

 bloom at the time of oviposition the egg is placed on the open 

 flower ; the proboscis may be thrust into a flower during oviposition, 

 but it is certainly the exception and not the rule. The moth 

 appears to lay but one egg on a flower-head, but, on one occasion, he 

 found five placed singly on a single flower-head, on another a 

 cluster of three, and several times two, but his observation leads 

 him to doubt their being laid by the same individual. He further 

 notes that it is recorded that the abdomen is turned upwards when 

 egglaying, but that he never saw any attempt whatever at an upward 

 movement although he watched most carefully. Of five ova 

 deposited on July nth, iqoi, one hatched on July 15th and four 

 on July 1 6th, this giving, in this case, an oval period of only 4 — 5 

 days. Grote also notes mode of egglaying (Zoo/., p. 7153). 



Ovum. — Green in colour ; almost a sphere in form ; but it has 

 a longer (micropylar) axis and a circular outline at right angles 

 to this ; the length is almost exactly imm. and the transverse 

 diameter o^mra., some eggs are a little smaller than this, but the 

 diameters have the same ratio ; the micropyle was not made out ; 

 the surface sculpturing is in the form of a very shallow set of 

 pits, the lines of the netting being little raised above the general 

 surface ; the reticulation is of 5- and 6-sided pits of a diameter of 

 o'02mm, (Chapman. Described November 14th, 1901, from eggs 

 obtained by Head, of Scarborough). (1) Of a somewhat darker 

 green than the egg of Tkeretra porcellus, and more strongly 

 sculptured ; about o^mm. in length by o"8mm. in width, with a well- 

 marked rosette of cells around micropyle ; apparently quite filled 

 by contents and without depression (July, 1901. Laid on flowering 

 shoot of Galium aparine). (2) A short rounded oval, flattened 

 and depressed at sides, small, and of a bright semitransparent 

 green colour ; about imm. in length, o*9mm. in width, and about 0*9- 

 o - 8mm. in thickness ; the surface smooth and pearly, but not highly 

 varnished ; with a shallow and poorly marked surface cell-pitting 

 (July 29th, 1900. Laid on flower, pedicels of Galium verum) [BacotJ. 

 Almost exactly imm. in length, and only just under imm. in 

 width, the outline being almost a circle, the height rather less than 

 the width, still the egg has the general appearance of being nearly 

 spherical, some with a fairly large, irregularly oval, hollow depression 

 on the upper surface (opposite point of attachment) others without ; 

 the surface distinctly covered with an irregular polygonal reticulation, 

 the network becoming more distinct at the micropylar end, which is 

 somewhat flattened ■ the micropyle appears to be composed of a 

 number of radiating cells which outwardly distinctly run into the 

 surrounding cells that form the ordinary network ; colour at first 

 bright pea-green, changing to yellowish with green areas as the 

 embryo matures ; the shell is quite transparent, and the embryo 

 is very distinctly to be seen through it, and the structure of the 

 young larva, and its striking bifid hairs may be clearly distinguished 

 [Tutt. Described July 10th, 1901, from eggs found attached firmly 

 to leaves of Galium verum by Mr. Ransom, a few days previously]. 



