SCIENCE- GOSSIP. 



295 



arrangement of the letters of the Greek alphabet. 

 Some other principle underlies the habits of the 

 mother ichneumon fly. On the other hand, in the 

 case of the larvae, if they do not attack the vital 

 organs of their victim till the last moment, it may 

 be that their jaws are not powerful enough to 

 devour the tougher parts ; and this argument is 

 probably true. 



Of the many other species of ichneumon, all of 

 which differ in their habits, the Scotia, flavifrom, 

 for instance, lays its eggs on the surface of the 

 larvae of a large beetle, to wrhich it affixes them by 

 means of an adhesive liquid. At birth these larvae 

 emerge only in part from the egg ; they push out 

 the head just far enough to enable them to feed 

 upon their victim. Another ichneumon, the 

 Ephialtes, evinces a remarkable power of discover- 

 ing the larvae of other insects hidden in the bark of 

 trees. The insect runs up and down the bark, 

 striking it at intervals with its borer, as if to sound 

 the presence of its victim. All at once it halts and 

 remains motionless for a few seconds ; it has 

 discovered a larva. Through a tiny aperture in 

 the bark it insinuates the needle-pointe;! ovipositor 

 and deposits its eggs upon the larva. 



In the several species of these ichneumons the 



length of the ovipositor varies, and is proportionate,- 

 in length, to the thickness of the bark upon which 

 each species lives. The inhabiting of a particular 

 tree by these insects is not a matter of choice, but of 

 necessity, since their organs are adapted to spec:'al 

 functions that can only be discharged on the tree 

 specially suited to each species. 



There is another ichneumon equally conspicuous, 

 and for many reasons interesting to the entymo- 

 logist. This insect selects neither the interior nor 

 the surface of the larval body, but deposits its eggs 

 inside the eggs of other insects. In separate eggs 

 it deposits one of its own. This is hatched before 

 that which forms the nidus, and the contents are 

 consumed by the parasitic larva. De Geer, the 

 Swedish naturalist, was, I believe, the first to 

 observe and record this interesting fact. He had 

 secured a leaf upon which a number of eggs were 

 fixed, preserved it with great care, anticipating a 

 brood of butterflies, and was greatly surprised 

 when a tiny ichneumon fly emerged from the egg. 

 The lepidopterologists who breed butterflies from 

 chrysalides or eggs may be disappointed by having 

 merely a brood of ichneumon flies issue from them. 



{To he continued.) 



OUR COCKROACHES. 



By E. J. Burgess Sopp, F.E.Met.Soc, F.B.S. 



(Continued from pacj ; 2G0.) 



TT7RITING early in the seventeenth century, 

 * ^ Moufet records the occurrence of Blatta 

 orientalis in cellars and flour mills in London, but 

 it had probably been established in England some 

 considerable period antecedent to that time (.'■*)• 

 His quaint drawings of the species, however, include" 

 amongst them the figure of a Blaps, the " darkling- 

 beetle " of some of our older writers ('^), a hetero- 

 merous coleopteron of somewhat similar habitat, 

 but whose hard convex form and slow deliberate 

 gait have little in common with the appearance 

 and activity of the cockroach. He further says : " I 

 have heard from persons of good credit that one 

 of these cockroaches was found and taken in the 

 top of the roof of the church at Peterborough 

 which was six times /larger than the common 

 species, and which not only pierced the skin of 

 those which endeavoured to seize it, but bit so 

 deep as to draw blood in great quantity. It was a 

 thumb's length and breadth in size, and, being- 

 confined in a cavity of the wall, after two or three 

 days made its escape no one knew how " ("^). If 



(14) Baker, " Phil. Trans.," 1740, p. 441 ; Kirby and Spencc, 

 '• Intro. Entom.," 7th edit., p. 416. 



(15) It was probably introduced during the sixteentli 

 cantury. Originally a native of Central Asia, it lias now spread 

 with trade all over Europe. 



(16) " Insectorum Theatrum " (1634). 



this fearsome creature were indeed a cockroach, 

 and the " persons of good credit "had in nowise 

 exaggerated its proportions, it might possibly have 

 been a nearly allied insect to our occas-ional visitant 

 Blahera gigantea (fig. 13), .subsequently alluded to 

 herein. The celebrated Dutch naturalist, Johannes 

 Swammerdam ('"), was also acquainted with the 

 cockroach. Amongst his " creatures of the second 

 class " we find mention of " the Indian insect, 

 sufiBciently known by the name of kakkerlak" C^), 

 and " that species of beetles which are commonly 

 found about bakers' ovens and, according to Fabius 

 Columna, in kitchen dirt. They agree altogether 

 with the insects just now mentioned and called 

 kakkerlak, and are the same that are described by 

 Moufet under the name of Blattae." In a recent 

 communication to the " Annals of Scottish Natural 

 History" (January 1901) ('^) Mr. Evans called 

 attention to three old and very interesting lists of 

 Scottish insects, in the earliest of which, by 



(17) " The Book of Nature," Lo'idon, 1758 (first pub. 1669). 



(18) Kakerlac, a name of probably Dutch origin used for the 

 Blattae Ijy the American colonists 0' Nat. Cyclopedia," London, 

 1847). Latreille divided the cockroaches into two divisions, 

 Blattae and Kakerlac, the former containing those insects in 

 which both sexes possessed wings, and the latter comprising 

 those in which the females are apterous, as in B. orientalis. 



(19) "Ent. Eecord," xiii. 5. See also Kirby and Spence 

 ," Int o. Eutom.," p. 151 (7th edit.). 



