MODES OF REPRODUCTION 323 



inches in length and about four months old still attended by the 

 father. The following description of the habits of the male 

 when in a charge of a swarm of young is given by Bashford 

 Dean from direct observation : " In a slow and cautious way 

 he circles about, now over and now under his swarming charges, 

 watchful apparently that the stragglers shall keep up to the 

 rest ; and in their turn the young fish seem to fully realise that 

 it is their duty to keep as close as possible to their guardian. 

 It was found by no means easy to approach the male fish with- 

 out attracting his notice; he appears to be constantly watchful 

 and when alarmed exhibits the greatest solicitude for his 

 charges. Sometimes he backs quietly into some reed-screened 

 pool, hiding below in the shadow of floating weeds, his presence 

 only betrayed by the black mass of larvae about him ; at other 

 times he will sulk cautiously away, drawing the swarm after 

 him as rapidly as possible. His duty is clearly to care for his 

 charges and when he finds it impossible to carry them off with 

 him, he will in the majority of cases remain quietly and face 

 the enemy. In one instance he was actually pushed away. 

 There can be no question that the feeling of alarm of the 

 guardian may be transmitted to the young, for in case of need 

 the swarm can be moved more rapidly, the young, excited in 

 their movements, appearing to draw more closely together ; 

 under all circumstances they appear to be careful not to disperse. 

 When the male has been driven away the swarm sometimes 

 becomes so dense that it may be taken almost to a fish by a 

 single dip of the scap-net; if not interfered with it will gradu- 

 ally move away and take refuge among the floating weeds often 

 so perfectly that no trace of it can be noticed." 



Several of the tropical fishes of the primitive families Mor- 

 myridae and Osteoglossidae, build remarkable nests which have 

 been described by the late J. S. Budgett, a young Cambridge 

 zoologist, whose premature and much-regretted death was di- 

 rectly due to disease contracted on his scientific expeditions to 

 the swamps of West and Central Africa. Gymnarchns, one of 

 the Mormyridae which has a long dorsal fin, but neither pelvic, 

 anal, nor caudal fins, makes a floating nest of grasses. The 

 whole nest is about two feet long by a foot broad. Three of 

 its sides project above the surface of the water, the fourth side 

 is about two inches, and the bottom about six inches below the 



