S2 EVOLUTION IN THE PAST 



Finally, it must be supposed, the waters in these great 

 peat regions acquired a lasting predominance ; and the 

 series of black seams in the strata was brought to an end. 

 INSECTS Carboniferous brakes and forests must have swarmed with 

 insects, winged and wingless. Primitive cockroaches (Pro- 

 gonoblattina, etc.), locusts, and grasshoppers appear to have 

 been especially numerous (Palceacrididce}. May-flies flitted 

 about (Palingenia, Homaloneura) ; and forerunners of dragon- 

 flies were also on the wing (Protodonates). Some allied forms 

 were enormous creatures, with bodies a foot and a half in 

 length (Meganeura). Other of the insects apparently were 

 wingless, and were probably spring-tails of primitive de- 

 scription (Dasypeltus). Early forms of stick and leaf insects 

 were also in the woods (Protophasmida) ; and some relations 

 of present-day snake-flies (Miamia). Most of the insects, 

 however, although comparable with living forms, were more 

 intermixed in their relationships than is the case in modern 

 insect-life. They were all probably either predaceous in 

 habit or suctorial, subsisting chiefly on juices of plants. 

 Environment was not yet favourable for the evolution of 

 flower-lovers and gatherers of honey. 



MYRIAPODS Millepedes first known in the Devonian were now 

 SCORPIONS represented by many species. Certain scorpions by this 

 time had developed lungs, and taken to living more or less 

 SPIDERS on land (Eoscorpius). Various ancestral types of spiders were 

 now abroad (Anthracomartidce). Some specialised forms 

 (Geralinura, Eophrynus) resembled the predaceous scorpion- 

 spiders of our own time (Pedipalpi} ; and true spiders were 

 AIR- beginning to appear (Protolycosa, Palasanea). Land life was 



BREATHING also diversified by certain snails that had completely lost 

 GASTROPODS touch with their briny relations (Dendropupa). 



Marine life was in a condition of vigorous development. 

 SPONGES Sponges with simple rod-like needles and improved canal- 

 systems became much more prominent (Monactinellids) : and 

 the older known forms, rigid with artistically arranged 

 needles, were flourishing in quiet waters (Tetractinellids, 

 Hexactinellids). Some new sponges now appeared with 

 needles more numerously rayed than any earlier forms. The 

 supports for the " fleshy " organism were irregularly dis- 



