104 Mr Budgett, The Habits and Development, etc. 



to the rootlets thus laid bare. The hatched larvae are provided 

 with six cement organs on the surface of the head. From them 

 a delicate rope of mucus is spun often nearly the length of the 

 body of the larva ; by this fine rope the larvae hang suspended 

 from the rootlets until the yolk-sac is absorbed. 



It is remarkable that the larvae of Gymnarchus and Heterotis 

 are both provided with long protruding gill filaments which have 

 hitherto, I believe, been only once recorded in the Teleostomi ; 

 and that Sarcodaces and Hyperopisus are provided with con- 

 spicuous cement organs on the head ; these cement organs on the 

 head of the larva have usually been regarded as characteristic of the 

 Ganoidi. 



It is thus seen that the conditions by which fishes, which breed 

 in tropical fresh waters, are surrounded is conducive to the develop- 

 ment of very various accessory organs in the larva, both for the 

 purpose of respiration and also of preserving them from harmful 

 contact with their surroundings. 



