1886.] Mr Gardiner, On attachment of Laminar ia bulbosa. 433 



which is Weber's result*. This integral can be easily evaluated 

 in the form 



2 2c 



= - sin 



7r p + q' 



when jj 2 = r 2 + c 2 + 2rc sin#, 



<f = r 2 + c 2 — 2rc sin6>, 

 which is the well-known expression for V. 



15th April, 1886. 



May 24, 1886. 



Professor Foster, President, in the chair, 



Mr H. F. Newall, M.A., Trinity College, was duly elected a 

 Fellow of the Society, and Mr Percy Groom, of Trinity College, 

 an Associate. 



The following communications were made to the Society : — ■ 



(1) On a New Species of Dinophilus. Bv W. F. R. Weldon, 

 M.A. 



(2) On the life-history of Pedicellina. By S. F. HarmeR, B.A. 



(3) On the organ of attachment of Laminaria bulbosa. By 

 Walter Gardiner, M.A. 



The author stated that correlated with the flattened stem and 

 enormous leaf of this plant there were especial mechanical arrange- 

 ments to enable the organism to withstand the force of the wave- 

 beats to which it was continually exposed. The additional stability 

 was chiefly attained in two ways. First, the flattened stem twisted 

 upon itself at its basal portion ; and secondly, there was developed 

 just above the root a meristematic ring of tissue which rapidly 

 grew out on all sides, until finally in its adult state it formed the 

 well-known irregular bulbous structure so characteristic of the 

 species. The true root persists for some time, but gradually atro- 

 phies and disappears. From the bulbous portion, adventitious 

 roots arise which function in every way as root organs, and hold 

 the plant firmly to the substratum. 



* Borchardt's Journal, Vol. lxsv., p. 77. See also Heine, Vol. n., p. 192. 

 VOL. V. PT. VI. 30 



