424 Botanical Society of Edinburgh. 



hyosternals and hyposternals are primitively long, slender, trans- 

 verse bars, vi^hich join the vertebral ribs in the Tortoises and Terra- 

 penes, without the intervention of any marginal pieces. The ossifi- 

 cation of the superadded dermal portions proceeds from the pre- 

 viously ossified endo-skeletal elements. 



The author concurs with M. Rathke in regarding the marginal 

 pieces as ' dermal bones,' and concludes by a full discussion of the 

 facts and arguments which have led him to a different conclusion 

 respecting the nature and homologies of the carapace and plastron. 



The memoir is illustrated by figures of the carapace and pla- 

 stron, and of the corresponding segments of the skeleton in the bird 

 and crocodile, and of the development of the thoracic-abdominal case 

 in land- and sea-chelonians. 



BOTANICAL SOCIETY OF EDINBURGH. 



March 8, 1849. — Professor Balfour, President, in the Chair. 

 The following communications were read : — 



1. " On the mode of Growth in Calothrix and the allied genera," 

 by John Ralfs, Esq. (See p. 348 of the present number.) 



2. " On the Cone-like Bodies produced by Epilohium palustre," 

 by James Hardy, Esq. 



This paper describes the fleshy buds or hybernacula formed at the 

 ends of the scions of some species of Epilobium, and which constitute 

 a mode of propagation for those plants independently of the seed. 

 The author notices more especially those of E. palustre, which he 

 describes as resembling minute larch- cones, and formed of smooth, 

 fleshy, orbicular reniform or cordate scales. The basal pair is small, 

 the following ones suddenly enlarged, the apical ones small. They 

 are imbricated in pairs alternately. Iii the autumn their connection 

 with the parent plant is dissolved, and they lie loose on the spongy 

 soil until the spring, when they produce roots and form new and 

 distinct plants. 



3. " On Varieties of some common Plants," by James Hardy, Esq. 

 The author describes a state of Scabiosa succisa with the involucre 



small, the heads loose and few-flowered, the external segment of the 

 corolla much lengthened, stigma and stamens short. Found in Pen- 

 manshiel Wood, Berwickshire. He next notices two forms of Leon- 

 todon Taraxacum [Taraxacum officinaW] founded chiefly on the forms 

 of the leaves, characters quite unworthy of confidence in that genus. 

 Of Rumex crispus he remarks that each of the petals bears a tubercle 

 when the plant grows near the sea, and only one of them when in- 

 land. [This seems to be a generalization from insufficient data.] A 

 variety of Sonchus oleraceus is founded on the presence of glands on 

 the involucre, flower-stalks very downy when young, leaves lyrate- 

 pinnatifid and usually destitute of spines. It is " maritime and is 

 rarely found beyond the influence of the sea." [We have before U3 

 several specimens of S. oleraceus to which these characters will more 

 or less apply, but only one of them is maritime. Gaudin is the only 

 author with which we are acquainted who notices a plant (his /3. glan- 



