KNOWLEDGE. 



[Jandary, 1902. 



used to nm through it a bont pin attached to a thread 

 801110 eight or nine feet long. TIio end of the thread 

 being heUl in the boy's hand, tlie roclcchafer was tossed 

 into the air, when of course it spread its wings and 

 tried to fly away, but was kept like a captive balloon, 

 struggling at the end of the string. This was the well- 

 known and very ancient pastime of cockchafer-spinning. 



-Sralos of Cockc'liftIV 



-Antenna of Malo 

 Cockrlmfev. 



The sport seems to have been known even to the Greeks 

 some 2400 years ago, but the Greek boys contented them- 

 selves with tying the string to the insect's leg instead 

 of running it tlirough the tail. To judge from an 

 illuminated illustration contained in a 14th century MS., 

 the British youth practised a similar sport with 

 butterflies. 



The wings, which are folded away most daintily under 

 their brown covers, are of stout membrane, much 

 strengthened along the outer border to give them the 

 firmness of stroke necessary for raising into and main- 

 taining in the air so bulky a body. These wings are 

 about twice as long as their covers, and consequently 

 have to be folded crosswise in the middle before they 

 can bo stowed away. They are the sole organs of flight, 

 and the buzzing sound they produce has given the 

 insects the name of " chafers," though this name is not 

 confined to the present species, but is technically applied 

 to the whole tribe of which it is a representative. This 

 tribe is not numerously represented in Britain, but in 

 tropical regions there are an immense number of species, 

 which include some of the largest and some of the 

 handsomest beetles in the world. The prefix " cock," 

 which distinguishes the present species, is considered by 

 Dr. Mun-ay to imply strength or valour, or to have 

 reference to the practice of making the insects fight, so 

 that it would be equivalent to the " strong or valiant 

 buzzer." 



Unquestionably the most beautiful part in the 

 structure of a cockchafer is the antennaj. These, again, 

 differ in the sexes, those of the male being the more 

 graceful and elegant. Each consists of ten joints, of 

 which the basal one carries a brush of hairs, and the 

 last seven are extremely short, each furnished in the 

 malo with a long leaf-like flap on its inner surface. The 

 flaps lie close together when the animal is at rest, but 

 when it is on the alert, they are opened out like the 

 leaves of a book, so as to give a beautiful fan-like 

 appearance (Fig. 3). The opening of these leaves seems 

 to imply an attitude of attention, so that it corresponds 

 to the pricking up of the ears on the part of a vei-te- 

 brate. In the female the basal leaf is missing, the 

 corresponding joint being furnished only with a short 

 spine, so that there are but six leaves, and they arc 

 both narrower and shorter. Each loaf is closely covered 

 on both surfaces with little pits or depressions, from 

 the centre of which springs a minute hair. From their 

 structure one can hardly doubt that they are highly 

 senj;itivc organs, though it may not be easy to say what 

 i^ the precise signification of their curious shape. That 

 they are larger and handsomer in the male suggests the 



possibility of their having something to do with sexual 

 selection. That they are not, however, purely ornamental 

 follows from their sensitiveness and from the fact that 

 the insects arc cjuicscent in daylight, when personal 

 attractions might count, and active towards dusk, when 

 they could not easily be perceived. 



I have spoken above of the tenacity of grip these 

 insects manifest, and when the structure of the feet is 

 examined, there can bo no surprise that they are so 

 diflicult to dislodge. At the end of each foot are two 

 strong hooked claws, each with a couple of teeth at the 

 base beneath, and with the terminal portion of the claw 

 delicately grooved (Fig. 4), all of which peculiarities 

 help to make them effective clinging organs. In this 

 part of her stiiicture the female insect has the advantage, 

 as the basal teeth are considerably larger and more 

 powerful in that sex than in the male. 



Having thus given my readers svigge.stions as to those 

 parts of the cockchafer's external anatomy which are 

 most worthy of examination, I must ])ass on to consider 

 the insect in the earlier stages of its career, and to 

 sketch its life^history. Unlike the majority of insects, 

 it is gifted with considerable longevity, living, in one 

 or other of its forms, thiough four distinct summer 

 seasons. The eggs are laid in May, and as the lai-va 

 is subteiTanean in its habits, the female lays her eggs 

 underground, selecting a site for the purpose where tho 

 soil is loose and di-y. She descends about six or eight 

 inches below the surface and lays a batch of from thirty 

 to thirty-five eggs, and she may spend some two or three 

 days in the operation, remaining buried all the time. 

 A few days afterwards she again works her way down 

 through the soil and lays another batch in a different 

 place. Three times in succession will this, as a rule, 

 bo done, and the more vigorous insects will even lay four 

 batches of eggs. The number diminishes somewhat in 

 the successive batches, but we may say that each vigorous 

 female cockchafer may become the parent of from sixty 

 to eighty young, a rate of multiplication which easily 

 explains the enonnous numbers of the insects which are 

 sometimes met with. A little calculation will show that 

 if a female lays on the average sixty eggs, and if no 

 more than one-third of these on the average 

 produce females, yet in about twenty yeai-s, the 

 descendants then alive of the female cockchafer would 

 amount to upwards of 180 millions, supposing that no 



Fig 4.— Claws of Coekc-Uafcr. 

 a. Male. h. Female. 



Fiii. 5. — Larva of Corkchafei'. 



accidents have happened. That the insects do not 

 appreciably increase in numbers therefore shows how 

 cxlonsive the chapter of accidents must be. The mothers 

 seem to suffer from a disease which sometimes brings 

 about the putrefaction of the eggs before they are laid, 

 while the armies of rooks, jackdaws and other birds mako 

 persistent and successful warfare upon the larv.-e. 



About six weeks after the laying, the eggs, which are 

 at first oval, but afterwards become almost spherical, 

 hatch, producing little fat whitish grubs, each with six 

 logs close behind the head, and a pair of good biting 

 jaws on their disproportionately large heads. Their food 



