BY HENRY TRYON. | Oe 
444, p. 11,] where, writing of a ‘ Confera ’ produced in excessive 
quantities in the Lakes forming the estuary of the Murray, on 
the shores of which he states it is blown up as a thick green 
scum, the crusts so formed passing through the Murray mouth 
into the ocean, to be afterwards wafted ashore; he goes on to 
relate that this scum is swallowed by cattle drinking at the 
edges of the lakes, and that it acts so poisonously on them as to 
rapidly cause death. The symptoms are stated to be stupor and 
unconsciousness, falling and remaining quiet, as if asleep, unless 
touched, when convulsions come on, with head and neck drawn 
back by rigid spasm which subsides before death. Time: sheep, 
1—8 hours; horses, 8—24 hours; dogs, 4 to 5 hours; and pigs, 
3 to 4 hours. The pathological appearances, as revealed by 
p.m. examination, are then.given, and a verdict pronounced 
that the plant is rapidly absorbed into the circulation, acts as a 
ferment, and causes disorganisation. 
Although this alga—so poisonous in its properties—is said to 
originate in these estuarine lakes, and to be wafted out to sea, 
and afterwards washed ashore. The alternative supposition 
that is brought in the first instance from the ocean at flood-tide 
does not appear to have been entertained. However, the physi- 
cal properties of the scum, especially the colour and opalesence* 
(which appear to be simply due to chlorophyl in solution) of 
solutions derived from it, indicate a near alliance with the 
Trichodesmium of Moreton Bay, and certainly point to one of 
* The isolated occurrence of one or other of the properties pre- 
sented by Trichodesmium, and under similar conditions, may refer the 
phenomenon to animal or plant life floating or suspended in the water, 
and not necessaFily to Trichodesmium itself. Notices of such appear- 
ances are to be found in various books of travel, and have been given 
by Peron, as is pointed out by Darwin, who also adds somewhat to the 
bibliography of the subject. (‘* Voyage of the Beagle,’’ Ed. 1884, p. 16, 
note). For a complete account of the circumstances attendant on the 
undoubted presence of Trichodesmium, however, and in cases where its 
presence has been experimentally demonstrated, the readeris referred to the 
graphic narrative of Darwin himself and tothoseof Ehrenberg and Dupont. 
