514 FISHES CHAP. 
its long summer nap. It is highly probable that the exceptionally 
numerous leucocytes act as carriers in the work of transporting 
the fatty particles to the different organs and tissues of the body. 
The length of the summer sleep naturally varies with the duration 
of the dry season, and probably it lasts on an average nearly half 
the year (August to December). The cocoons, imbedded in an 
outward casing of hardened mud, have often been brought to Europe, 
and when placed in water of suitable temperature the long torpid 
Protopterus escapes from its prison in a perfectly healthy con- 
dition, and resumes its partly branchial and partly pulmonary 
mode of breathing. The negroes of the West Coast of Africa are 
very partial to these Fishes, which they dig out of the dried 
marshes and preserve in their clumps of mud for food. With 
the advent of the rainy season, when the marshes become flooded, 
the Protopterus emerges from its cocoon, and returning to its 
former active hfe, soon enters upon the task of reproducing its 
kind. The important observations of Budgett' have thrown 
much light on the curious breeding habits and development of 
these Fishes. The Fish makes a nest near the edge of a swamp. 
The nest is simply a hole of irregular shape, about a foot 
in depth, filled with water and ‘surrounded by long grass (Fig. 
308). There is no lining to the nest, and the eggs are deposited 
on the bare mud. Until the eggs are hatched, which occurs 
about the eighth day, and while the larvae are in the nest, the 
male remains on guard, and is apt to bite severely an incautious 
intruder. Probably with the view of aerating the eggs the 
water is continually lashed about by the tail of the guardian 
parent. The male has no trace of the peculiar vascular filaments 
which adorn the pelvic limbs of the male Lepidosiren during the 
breeding season. The early developmental stages are similar in 
their main outlines to those of Neoceratodus, but the young are 
very different. When the young Protopterus (Fig. 509) is hatched 
it is provided with a crescentic glandular sucker or cement-organ, 
situated on the under side of the head behind the mouth, by 
means of which the larva attaches itself to the sides of the nest, 
or of the vessel in which it is confined, much in the same way as 
the young Lepidosteus, and probably for the same reason. It 
may be remarked that the sucker agrees in structure, position, 
and function with that found in Amphibian tadpoles, but it 
1 Trans. Zool. Soc. xvi. Pt. ii. 1901, p. 119. 
