director's report. 77 



The ejector, used for forcing water from the sea, has again been a source 

 of trouble. The iron rod supporting the lower bucket of the automatic 

 valve had rusted so seriously, that it was no longer able to bear the 

 weight, and the bucket became detached. In order to repair this defect 

 it was necessary to remove the cover of the lower chamber of the 

 apparatus, an undertaking of some difficulty. The matter has, however, 

 now been put right, the iron rod having been replaced by one of Muntz 

 metal, which, it is hoped, will better resist the action of the sea-water. 

 The engines and rotary pumps are also being put into a state of 

 thorough repair. 



The new system adopted for supplying the tanks in the Laboratory 

 with sea-water has shown itself to be a decided improvement upon that 

 originally used. It may be of interest to describe somewhat in detail the 

 method now employed. Water is pumped from the sea at higli tide — 

 when possible, only at the highest spring tides — into one of the large 

 underground reservoirs. From thence it is pumped 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 them- 

 selves about one-half, the water running from them falling into the 

 Aquarium below. The Aquarium, however, is supplied principally by a 

 constant circulation of water from the second underground reservoir, 

 which thus becomes gradually renewed by the water falling into it 

 from the Laboratory. By this arrangement the water supplied in the 

 Laboratory is such only as has not previously 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 that in the general circulation of 

 the Aquarium. Foraminifera, which formerly did not develop 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 up all around their 

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

 of hydroids, serpulids, and compound ascidians. In these tanks the 

 most varied animals, including Hydractinia, Sponges, Echinus, Aplysia, 

 and Ascidians have remained quite healthy for several months, and 

 appear to be still in the same condition. From this and other experi- 

 ments which I have made, I feel little doubt that the direct action of 

 sunlight upon a portion, 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 presence of sunlight also that sea- 

 weeds will grow, and in an aquarium where these grow in quantity 



