RUDIMENTARY EYES 729 



those Polychsetes which burrow in the sand or mud of the sea-shore may be 

 without visual organs (the lob-worm, Arenicola marina) ^ ; sometimes the 

 larval forms have eyes which disappear on reaching adulthood (Tampi, 

 1949). Similarly, sand-burrowing Molluscs may be unprovided with eyes 

 (elephant's tooth shell, Dentalium)." Among Arthropods, those ]M\Tiapods 

 which burrow in moist forest debris may lack eyes (Pauropus),^ as well as 

 certain burrowing tyf)es of woodlice (Arcangeli, 1933). Among Insects 

 the primitive minute Protura which burrow in moist soils impregnated 

 with organic debris and are widely found in Euroj^e, America and India, 

 are without eyes, antennae and ^ings ; but the most interesting eyeless 

 insects are termites and ants. 



Termites (Isoptera), often mistakenly called " white ants,"" are widely 

 found in Europe, Asia and Africa but are unrepresented in Great Britain ; 



Fig. 873. — Termite Fig. 874. — Male Driver Fig. 87.5. — Female Dri- 



SoLDiER. Ant. ver Ant. 



while they are extremely sensitive to light, most are blind and are completely 

 without eyes (Fig. 873). They live in teeming millions in vast underground 

 communities governed by a complex and efficient social system and alive 

 with an immense and ordered business ; nevertheless, blind and eyeless 

 though they are, they conduct long regimented marches overland to seek 

 and convey back the wood they eat, and the young alates temj)orarily 

 develop wings in a frequently disastrous nuptial flight in the air. 



Most ants (Formicidse) have large and well-developed compound eyes 

 but in some forms of Dorylinte which dwell under the ground, eyes are 

 lacking. The wandering ants {Eciton) of Central and South America show 

 eyes in various stages of disappearance — small eyes without an optic nerve. 

 orbital sockets without an eye, and so on — while the female driver ant 

 {Dorylus) of Africa has no evidence of ocular or orbital remnants whatever. 

 It is interesting and perhaps significant that in the latter species the winged 

 male is possessed of eyes surpassing those of most insects, while all females, 

 whether queen, fighter or worker, are blind (Figs. 874-5) (Maeterlinck, 

 1927-30 ; Marais, 1937). 



It would seem probable that like all other members of the Hymenojatera (wasps, 

 bees, etc.) all ants were originally sighted and it might seem logical that the under- 

 ground types might tend to lose their eyes ; but why the eyeless female should continue 

 1 p. 191. 2 p. 197. 3 p. 211. 



