ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 393 



with Kuliu, among the Siphonaceee. Its parasitic character is tbe 

 only point which gives countenance to the idea that it presents a 

 transitional form between Alg^ and Fungi, All that can bo certainlv 

 stated of this organism is that it is an alga which inhabits the leaves 

 and leaf-cells of Arisarum vulgare ; and that its spores pass through 

 a resting stage outside the host. 



Structure of Corallina.* — Count Solms-Laubach has carried on a 



series of observations, in the zoological station at Naples, on the 

 structure of Corallina and its allies. The strong calcification of the 

 cell- walls, and the scarcity of the sexual plants, present great difficulties 

 in the way of their examination. 



There is no difference in the origin of the tetrasporangia and of 

 the conceptacles of the sexual organs in Corallina. The apex of a 

 shoot first of all becomes dej)ressed, and then hollowed out with a 

 more or less narrow opening. At the bottom of this cavity are found, 

 in the tetrasporangia, elongated cells, the transverse division of which 

 produces the tetraspores with intermediate paraphyses. The con- 

 ceptacles which produce the spermatia bear a close resemblance to the 

 spermogonia of fungi. The filaments which bear the spermatia project 

 from the opening ; at their extremities are from two to four minute 

 cells, each of which bears a tuft of very fine sterigma-like threads ; 

 and from these sterigmata the spermatia are separated by abstriction. 

 When free the spermatium appears as if tailed, from a piece of the 

 bterigma still remaining attached to it. 



The procarps are formed from the cells which make up the floor 

 of the conceptacle. Their development advances from the centre 

 towards the margin ; but while the central trichogyne becomes in the 

 meantime prepared for impregnation by a club-like swelling at its 

 apex, they become smaller and less frequent towards the margin, and 

 the outermost procarps of all have no trichogynes in a receptive 

 condition. Notwithstanding this, the production of spores commences 

 with the marginal procarps. While in the majority of the Florideaa 

 each procarp produces a cystocarp, in Corallina only one is formed in 

 each conceptacle, resulting from the development of all the procarps. 

 After impregnation all the carpogenous cells of the procarp coalesce 

 laterally by resorption of the separating walls. The " carpogenous 

 fusion-cell " thus formed developes the spores from its entire margin ; 

 in C. mediterranea club-shaped cells are produced in great numbers 

 from the indented edge, are separated by a wall from the fusion-cell, 

 and produce the spores by transverse division. This process exhibits 

 a hitherto unknown variety in the mode of producing fruit, resembling 

 in some respects that in Dudresnaya. 



The author draws a comparison between the " sister procarps " of 

 Dudresnaya, and the oosphere and synergidae or " sister-archegouia " 

 of AngiospeiTHS. 



The treatise concludes with a description of the allied genera 

 Amphiroa, Melohesia, Lithophylluin, and Lithothammon, especially as 



* Graf zu Solms-Laubach, ' Coralliua : eiue Mouogiaphio,' 18S1 (3 pis.).. 

 See Bot. Ztg., xxxix. (1881) p. 795. 



Ser. 2.— Vol. II. 2 D 



