DELSMAN: Fish Eggs and Larvae. 105 
backwards. The little spines persist longest on the tail, where they appeared 
latest. Thus in a fish of 150 mm (without the caudal flagellum) I found 
the spines still present on the tail and the hindmost part of the trunk, while 
on the larger anterior part of the trunk the skin had become smooth. 
Though in general parental care may be called an exception among 
fishes and especially among sea-fishes, it is very common within the 
highly specialised group of the Gasterosteiformes. The sticklebacks build a 
nest and the male watches over the eggs. Marsupial pouches are developed 
in the femile of Solenostomus and the male of Syngnathus and Hippo- 
campus.…lt is a general rule in the animal kingdom, which also holds in the 
case of fishes, that in forms where parental care is met with the eggs are 
larger than in those without. Fistularia is in this respect more primitive 
than its relatives. But we cannot wonder that in a member of such a group 
the eggs, though floating, yet belong to the larger pelagic ones. 
At the end of this article [ give an enumeration of the eggs and larvae 
of Fistularia caught in the vertical hauls during my cruises in 1919— 
1920. It appears that eggs and larvae have been caught during all six 
cruises, i.e. the whole year round, and at nearly every station. One might 
perhaps be inclined to conclude from the table given below that the eggs 
and larvae are more frequent in the eastern than in the western half of 
the Java Sea and that the same is the case with the month of March as 
compared with the other months of the year. However, | think the num- 
bers too small and one years observations insufficient to warrant conclusions. 
The total number of eggs and larvae of Fistularia caught during 
these cruises is 59, of which 34 eggs and 25 larvae. Working out provis- 
ionally the quantitative results of the six cruises | found that on an average 
the number of fish larvae is nearly twice as great as that of the fish eggs 
and a similar result has been reached for tropical seas by Hensen’s plankton 
expedition. In the case of Fistularia, however, this proportion appears 
to be the reverse, the eggs outnumbering the larvae. Yet this is just what 
we may expect with eggs with a relatively long development. In this case 
the egg-stage is relatively longer and the larval stage shorter than with 
species where the eggs hatch sooner. Consequently the number of eggs ata 
given moment will be greater and the number of larvae less than in the latter. 
The numbers placed in brackets relate to larvae, the others to eggs. 
KB CID BR GM NRC I IN OO) Re Sa AU 
July 1919 1 lie RN 2 Mae 
September 2 I hf Qype es 
November 3— | 311 (1) a) 2 222100) 1 1114 
January ’20 4 (1) (1) | eS) 
Merci Ds lil la lo) Kl lezohohïohal lol | 112 
May 6 bi (2) CON Lee) INC) 2(1)| 1 12 
34 + (25) = 59 
