WALKING-STTCKS AND WALKiyG-LEAVES. 79 



from the carboniferous beds. Both he and Scudder 

 have treated these fossils as forming a distinct family 

 called Protophasmidse. So far as we know them, these 

 early types differed from those of to-day by being 

 invariably winged, and in that both pairs of wings 

 were adapted for flight ; the front pair — what we now 

 call wing-covers, or tegmina — being not leathery and 

 thickened, as now, serving as mere protective flaps to 

 the closed hinder pair, but were as large and diaphanous 

 as their posterior fellows : these ancient insects explain 

 the origin of our living giants, being twenty-five to 

 fifty centimetres long, and as much as seventy in spread 

 of wing. To them have been referred, on inferential 

 grounds, a whole group of detached wings found in 

 carboniferous beds in Europe and America. The)- 

 further differed from modern types in having the several 

 parts of the thorax more nearly equal in length — 

 similar, in fact, to the condition while still in the egg 

 of walking-sticks of to-day ; thus illustrating once more, 

 what many naturalists believe, that in the development 

 of the individual we may trace, more or less completel)-, 

 the ancestral development of the race. 



The Phasmidce are a singularly isolated group ; we 

 discover no transition properly so called between this 

 family and others. So far as appearance goes, they 

 approach most closely the mantidse ; their forms are 

 sometimes very much alike ; in several mantids 



