IV 



COECII.IIDAE 



91 



runninj,^ water, and there lays about two dozen eggs. The egg- 

 strings lieconie ghied togeth(n\ oiitiingled into a bunch, and the 

 female coils lierself round the l)unch and remains in that posi- 

 tion, probably to protect the eggs against other burrowing 

 creatures, as blind snakes {Typhhyps and lihinophis) and certain 

 limbless lizards, with which the ground literally swarms. 1 'uriiig 

 t!iis kind of incubation the eggs assume a round shape, and grow 

 to twice their original size, and the mature cml»ryo weighs four 

 times as mucli as i\\(\ newlv laid egg. 



Tlie external gills are delicately fringed and red, and they 

 move u]i .nul down in the lluid of the egg. The body of the 



*W.r,^ 



Fii;. 1."). — frlitln/iqiliis ijlutindsa X 1. (Alter P. and F. Sarasiri.) 1, X nearly ripe embryo, 

 with gills, tail-fin, ami still with a consideralile ainonnt of yolk ; 2, female guard- 

 ing her eggs, coiled iiji in a hole underground ; -3. a bnncli of newly laid egg.s ; 

 4, a single egg, enlarged, schematised to show the twisted albundnous strings or 

 chalazai^ within the outer mcnilirane, whirh surrounds the white of the egg. 



embryo is at tirst white, hut becomes pigmented with dark grey. 

 A strong line of lateral sense-organs is formed, and a ring of them 

 lies around the eye and otliers on other parts of the head. 'I'he 

 short tail develops a fin. Of the three pairs of gills tlie third is 

 tlie shortest, and is generally turned dorsalwards. In embryos 

 of 4 cm. in length the longest gill measures as much as 2 cm. 

 Volk is still present in embryos which have reached the 

 surprising length of 7 cm. Then the gills begin to shrink a 

 little, and at tliis time one pair of gill-clefts breaks through at 

 the base of the third external gill. 



When the larvae are hatched the gills are lost. The young- 

 larva takes to the water in a gill-less state, and moves about 

 Hkc an eel. At the bottom of the gill-hole on each side two 

 arches are visible, aiul there are at this stage neither innri- nor 



