23 



namental shrubbery, are the principal sufferers. The grafts or 

 buds of the last summer, grown only a few feet, with a single strait 

 stem, are destroyed, or if, by chance, a bud be left beneath the 

 wound, a year's growth is lost, and the beauty of its form spoiled. 



We must now trace the progress of the embryo from its incuba- 

 tion till it descends to its long subterraneous abode, where we 

 found it. 



The time at which the eggs are fit for deposite is forty eight 

 hours after impregnation, or within a fraction of that time. They 

 are so transparent, that we can see indistinctly the features of the 

 future insect through the shell, and with a good glass they are still 

 more visible. The shell wears a pellucid, membranous appear- 

 ance; but notwithstanding their apparent delicacy, they retain their 

 contents longer than other eggs either of insects or birds. They 

 hatch in fifty two days. We saw a deposite on the fifth of June, 

 and marked the spot, and witnessed the parturient process on the 

 twenty eighth of July. On the fifteenth day after the deposite we 

 discovered a manifest change of colour and form in the eggs, which 

 increased gradually till the embryo assumed the form of a worm, 

 without legs, and a thicker cream colour succeeded to the shining, 

 pearl-like white. Instead of the previous well-defined shape, it 

 now becomes crooked, and the form of the head is obvious, while 

 the body takes on the form of a silk-worm wrapped up, in a cream- 

 coloured cocoon. The most distinct feature is now the eye, which 

 is well defined ten days before the shell is broken. The rings of 

 the body, and the legs are easily distinguished, laid close to the 

 abdomen. Immediately before birth a distinct motion is to be ob- 

 served in the. insect in the eggs, resembling the jerking of the tails of 

 butterflies and moths, in the chrysalis state, when they are disturbed. 

 We took several nests from a bough marked for observation at the 

 exact, time of maturity, and soon perceived the signs of parturition. 

 We placed some of the eggs between two scales of mica, and ap- 

 plied the microscope. The power of the glass brought upwards 

 f fifty within its focus, and the whole process was clear and satis- 

 factory. Temperature exerts a considerable influence on the pro- 



