1888-89.] Mr D. M‘Alpine on Bivalve Molluscs. 
743 
form, such as the Unio, wallowing in the soft mud, or roaming freely 
about in running or stagnant fresh water ; the anchored form, such 
as the Mytilus, riding securely at anchor on the shore-line by means 
of its byssus ; and the attached form, such as the Ostrea, normally 
fixed by one valve, and living in sea water, often several fathoms 
deep. The free form, the anchored form, and the attached form 
represent different stages of freedom of movement in the adult 
condition, and when observations are made on a sufficient number 
of species, we may expect to have fresh light thrown upon what is 
often referred to as the mysterious movements of the cilia. 
Further, while there are many points of interest suggested by 
this investigation, the following may perhaps claim special attention : 
— The rapidity and readiness of movement by the gill of Mytilus — 
rapid as the free-swimming Infusorian, and ready at the moment 
of detachment besides to move, not only horizontally, but vertically 
and inverted ; the duration of movement of the palp of Ostrea ; 
and the distinction between ciliary movement and ciliary motive- 
power. 
These facts are all capable of being turned to useful account 
apart from the immediate organisms supplying and elucidating 
them. 
Strophanthus hispidus — continued : Pharmacological 
Action. By Dr Thomas R. Fraser. 
(Abstract.) 
(Read June 3, 1889.) 
Strophanthus extract and Strophanthin are substances of great 
pharmacological activity, as, by subcutaneous administration, Stro- 
phanthin produces death in average-sized frogs with a dose of 4 qVo^ 
of a grain, and in rabbits weighing about 3 lbs. with a dose of 
-ig-th of a grain. The kind of action is the same with both sub- 
stances, and therefore Strophanthin may properly be regarded as 
the active principle of Strophanthus hispidus. In my preliminary 
communications I have already described the more important char- 
acteristics of the action, and, therefore, to-night I shall content 
myself with drawing attention to a few only of these characteristics. 
