2 5 8 



SCIENCE- GOSSIP. 



to say in his favour, and one may search entomo- 

 logical literature in vain, from Moufet's "Insec- 

 torum Theatrum " (1634) to Dr. Sharp's monograph 

 in the "Cambridge Natural History" (1895), for 

 any substantial testimony to the credit of the cock- 

 roach. One author, for instance, assures us that 

 this "pestiferous race of beings," i.e. cockroaches, 

 " are particularly noisome to collectors," though we 

 are not told in what way ; whilst again we learn 

 that " these nasty and voracious insects fly out in 

 the evenings and commit monstrous depredations 

 . . . they are very fond of ink and of oil into 

 which they are apt to fall and perish. In this 

 case they soon turn most offensively putrid, so 

 that a man might as well sit over the cadaverous 

 body of a large animal as write with the ink in 

 which they have died" ('). In common too with 

 its near ally, the earwig, the cockroach has often 

 been misunderstood, and occasionally maligned. 

 It has been seriously suggested that certain of his 

 ancestors constituted themselves one of the plagues 

 of Egypt ( 2 ), the Hebrew word " Oreb," usually 

 translated " fly," being rendered " beetle " by 

 Geddes and others, and the species designated by 

 Dr. Harris, " Nat. Hist, of Bible," Blatta aegyptiaoa 

 Linn., in which he has the support of Eosenmuller 

 and Michaelis, " Oriental Bible," nov. pp. 5, 28. 

 It must, however, be borne in mind, as pointed out 

 by Hope ( 3 ), that the word Blatta had not amongst 

 the ancients the restricted meaning which it now 

 enjoys, and there is no evidence to show that 

 " Oreb " would be more correctly rendered a swarm 

 of cockroaches than a plague of flies. 



The ancestry of our cockroaches extends so far 

 back in time, that they can well afford to waive 

 all claim to having played a questionable part in 

 Egyptian history, a paltry three or four thousand 

 years ago ; a period which, although to us dim 

 with antiquity, is but yesterday in the lineage of 

 the Blattidae. It is often asserted that the 

 oldest remains of a cockroach are those which 

 were found in the Caradoc Beds of Calvados in 

 France during 1884 by M. Douville, and named 

 after him Palaeoblattina domnllei. This is scarcely 

 confirmed by later authorities, who maintain that 

 the claim of these ancient wing-remains to be 

 considered orthopterous at all, rests on extremely 

 slender grounds, and that our oldest undoubted 

 cockroach remains are ultra-European. The most 

 archaic types at present known have been found 

 in the Lower Carboniferous strata of the United 

 States of America. This question of origin, how- 

 ever, does not concern us here, and we may well 

 leave its discussion to the geologists and palae- 

 ontologists, whom it more closely interests. In 

 either case the claim of the cockroach to extreme 



(1) " Nat. Hist, of Insects," Lond. vol. ii. 92. 



(2) " Bridgewater Treatise," ii. 357. 



(3) F. W. Hope, " Observations in Support of Opinion that 

 the Blatta or Cockroach cannot be considered the same insect as 

 Oreb," 8vo. Lond. 1839. 



antiquity is fully established, and in consideration 

 of the fact it may not prove uninteresting to 

 glance back for a moment to the conditions prevail- 

 ing in those far-off days, when its early ancestors 

 were known to exist. 



During Devonian times the amount of dry land 

 appearing above the waters had probably been 

 greater than in preceding ages. The earlier strata 

 of that system were principally laid down beneath 

 the sea, but later formations seem to have been 

 largely precipitated in extensive and probably 

 somewhat shallow inland seas or lakes. Ireland 

 was joined to England, and it is not unlikely that 

 one of the land-locked basins of Scotland ex- 

 tended across to the Irish region. The period was 

 one of considerable volcanic activity. Evidence 

 of both sub-aqueous and sub-aerial eruptions is 

 furnished in Britain, the former by the inter- 

 vening beds of lava in Devon, Cornwall, etc., the 

 latter by the Cheviots and Sidlaw Hills ( 4 ). 

 Shortly after the commencement of the Car- 

 boniferous period a general submergence of the 

 land occurred in this part of the globe, until 

 Britain was represented in prehistoric seas by an 

 archipelago, of which perhaps the largest islets con- 

 sisted of the higher land of Ireland, Scotland, a por- 

 tion of North Wales, the Midlands, and the Silurian 

 district of Cumberland. That long and continuous 

 submergence occurred, is evinced in many localities 

 by the thickness of the limestone deposits of the 

 earlier period, whilst the numerous bands of coal 

 and the alternation of land and marine fossils 

 point to subsequent frequent and often somewhat 

 rapid secular oscillations of the surface. During 

 these later periods of elevation vast forests 

 flourished on the boggy mud flats along the courses 

 of, and about the mouths of rivers, on the low 

 spongy margins of primeval lagoons or estuarine 

 waters, which were likened by the late Dr. Brown 

 to the mangrove swamps of the West African 

 rivers and Indian coast, or the cypress swamps of 

 the Lower Mississippi at the present day. Amongst 

 the debris of this rank vegetation and in the 

 tangled jungles that clothed the higher slopes, it 

 is probable early ancestors of our cockroaches 

 flourished, in a climate rather more tropical in 

 character than that of the Northern Island of New 

 Zealand now (Hooker), in an atmosphere slightly 

 more charged with carbonic acid than is ours, 

 which would conduce to a uniformity of tempera- 

 ture over wide areas at present differing consider- 

 ably in climate. I am aware this latter premise 

 has been rupudiated by many authorities ; Dubois, 

 for instance, goes so far as to say " the supposition 

 of a formerly greater amount of carbonic acid in 

 the atmosphere can no longer be seriously dis- 

 cussed " ( 5 ), but the enormous heat-retaining and 

 protecting power of carbonic acid was not until 

 recently known, all the earlier theories propounded 



(4) Robert Brown, " Our Earth," vol. ii. ch. 5. 



(5) " The Climates of the G-eologic.il Past," Eug. Dubois. 



