9 



The new system adopted for supplying' the tanks in tlie Tiaboratory witli sea-water has shown 

 itself to be a decided improvement upon that orin'iually used. It may be of interest to describe 

 somewhat in detail tlie metliod now emplnyed. Water is pumjjed from the sea iit high tide — 

 when possible, only at the liighest spring tides — into one of the large underground reservoirs. 

 From thence it is pumjied twice daily into the tanks in the centre of the Laboratory upstairs. In 

 the intervals between the pumpings (twelve hours) these tanks are allowed to empty themselves 

 about one-half, the water running from them falling into the Aquariiim below. The Aq^un.rium, 

 however, is supplied principially by a constant circulation of water from the second underground 

 reservoir, which thus becomes gradually renewed hy the water falling into it from the Laboratory. 

 By this arrangement the water supplied in the Laboratory is such only as has not ])reviousiy 

 been used, whilst at the same time the water in the second reservoir and the Aquarium is 

 constantly replaced by water from the sea. 



There can be no doubt that the water now in the tanks upstairs is much better for delicate 

 work than tluit in the general circulation of the Aquarium. Foraminifera, which formerly did not 

 develo]! normally in the water, can now be satisfactorily reared, and colonies of hydroids have 

 sprung up on the sides of the tanks. Two shallow wooden tanks, placed immediately under the 

 windows on the south side, have been especially successful. Green weeds have sprung uj) all 

 around their sides, together with a few tufts of red weeds, and numerous colonies of hydroids, 

 serpulids, and comjiound ascidians. In these tanks the most varied animals, including Hydractinia, 

 Sponges. Echinits, Aplysia, and Ascidians have remained quite healthy for several months, and 

 appear to be still in the same condition. From this and other exjieriments wliiidi 1 have made, 

 I feel little doulit that the direct action of suidight upon a j>ortion, at least, of the water is an 

 important factor in keeping it in a satisfactory condition to support the more delicate forms of 

 animal life. It is only in the jireseuce of sunlight also that sea-weeds will grow, and in an 

 A([uarium where these grow in quantity a much more abundant supply of the minute forms of 

 animal life which serve as food for the larger is invariably found. 



The Fishes 



ales 



" . . . Ami fish that with their fins ami sliiiiiii^ 

 Gliile under the gieen wave : . . . . 

 . . . part single, part witli mate 

 Graze the sea-weed their pasture, and tlirough grooves 

 Of coral stray, or sporting witli quick glance. 

 Show to the sun their waved coats, dropped with gold." 



Are obtained from Qneensclilf, Western Port, and other points in the Bay ; and it is in 

 obtaining snch sjiecimens, and landing them safely at the Aquarium, that the great difficulty 

 exists. In the first place, if a fish has been hooked the hook must be gently removed, and the 

 fish placed in the well of the boat, and then kept in a floating cage for some time, to become 

 accustomed to caiitivity — of com-se, the same 

 apjdies to fish caught in nets — and for transit to 

 Melbourne are placed in tins of various shapes, 

 which are jirovided with an iimer compartment 

 of stout calico, which is stretched all round to 

 23revent the fish being liiu't. The moment the 

 tins are stocked they must be sent off, and a 

 constant agitation kejit up in the water to retain 

 the fish alive. As an illustration of the amount 

 of oxygen recjuired by a fish, I may state that 

 almost any ordinary fish the size of one's hand 

 would exhaust the oxygen in a bucket of still 

 salt water in a quarter of an hour, and would 

 then die unless an artificial aeration was given 

 to the water by some vessel being dipjied into 

 the bucket and its contents being allowed to fall 

 some distance through the air to entangle oxygen 

 or forcing in air through a tube connected with a i)air of bellows. 



FISH CAhlilEItS. 



