68 
The period for which he was elected had now nearly ex- 
pired, and he understood that it was the intention of some 
members to support a motion for the repeal of the law which 
thus operated against his re-election. He wished, however, in 
order to prevent any mistake on this matter, to state that he 
did not intend to offer himself again as a candidate. He had 
received the office on the condition that he was to hold it only 
for five years, and he now thought that he was called upon to 
relinquish it absolutely into the hands of the Academy, and 
would not, therefore, offer himself for re-election. 
Mr. Donovan read a paper, entitled, ‘‘ Suggestions for the 
Improvement of Lighthouses.” 
Professor Allman read a paper on the Structure of the 
Muscular Fibre in the Polyzoa. 
“The muscles of the polyzoa are especially interesting in a 
physiological point of view, for they seem to present us with an 
example of true muscular tissue reduced to its simplest and 
essential form. A muscle may, indeed, in these animals, be 
viewed as a beautiful dissection, far surpassing the most refined 
preparation of the dissecting knife, for it is composed of a 
bundle of elementary fibres, totally separate from one another 
through their entire course. These fibres are distinctly marked 
with transverse striw, a condition, however, which is not at 
all times equally perceptible, and some of our best observers 
have denied to the polyzoa the existence of striated fibre. At 
the meeting of the British Association at Southampton I made 
known its occurrence in Cristatella, and have since, by repeated 
observation, satisfied myself of the striated condition of the 
fibre in the great retractor muscle in all the other fresh-water 
genera. In Paludicella 1 have seen this state beautifully 
marked through the pellucid cell, in the whole extent of the 
retractor muscle, while the fibres were on the stretch in the ex- 
serted condition of the polypide; and in all the other genera it 
