MISS Е. S. ВАВТОМ ОМ THE GENUS TURBINARIA. 223 
space (Pl. LV. fig. 2). It is possible that this layer of large papillate cells may serve for 
the secretion of mucilage ; but it has been difficult to come to any conclusion on this point, 
since all my investigation has been necessarily done on spirit and dried material. In the 
parts of the cavity which are lined by the narrow-celled central strand, the same meri- 
stematic division takes place, the conducting-cells dividing on their free side and forming 
the large papille in the same way as is done by the cortical parenchyma. When I had 
finished making these observations on the formation of the vesicle in Turbinaria, 1 
found that their schizogenetic development had been noted both by Dodel-Port (Biolo- 
gische Fragmente, i. Theil, p. 12) and by Valiante (Fauna und Flora des Golfes v. Neapel, 
Leipzig, 1883, p. 9) in the case of Cystoseira. Neither of these authors, however, 
mentions the subsequent formation of the papillate layer lining the cavity, and I can find 
no instance in which this growth has been already noticed. 
Vegetative Conceptacles.—Yhere has been some discussion as to the most correct 
expression to be used in speaking of these cavities, the “Fasergriibchen” of the 
Germans. Thuret (Etudes Рус. р. 32) speaks of them as “ cryptes piliféres,” and 
quotes in brackets “ pores mucipares, Auct.,” and “ cryptostomates, каш”; while the 
terms “sterile conceptacle” and “neutral conceptacle " have been proposed by Prof. 
Bower. The term “sterile conceptacle" is open to objection as conveying an idea of 
abortive growth, and even “neutral eonceptacle ” has the same tendency. Prof. Bower 
says (Quart. Journ. Micr. Sci. vol. хх. p. 37), “ Regarding the sexual conceptacle as the 
type of such structures, I have studied the development of it first, and then compared 
with it the development of the * Fasergrübchen, which I regard as an incomplete sexual 
conceptacle.” Oltmanns, on the other hand, takes the view that the fertile conceptacles 
are * Fasergriibchen” which have in course of time come to produce the organs of 
reproduction (l. c. р. 82), and objects оп this score to the term “neutral conceptacle." 
My own view of the matter is that the two forms of conceptacle are of equal antiquity, 
and were a later development in the ancestors of the Fucacez than the reproductive 
organs; therefore I consider neither form a development of the other, and the fact that 
one conceptacle contains reproduetive organs, the other nothing but paraphyses, is an 
interesting point, but does not bear on the phylogenetic history. of the conceptacles 
themselves. Following this theory, I propose to call the conceptacles which produce 
only paraphyses by the name of “ vegetative conceptacles," as deseribing those cavities 
in the thallus which have been developed only in a vegetative direction. They are freely 
scattered over the whole thallus of Turbinaria, occurring on the roots, stem, petiole, and 
lamina. Their mode of development in other Fucaceze has been minutely described by 
Prof. Bower (J. c.), Valiante (l. с. p. 11); and Oltmanns (7. с. p. 82), after referring to 
Bower’s investigations, adds the fact that the further changes of the initial cell may take 
place in one of three different ways. In Himanthalia it disappears altogether; in 
Halidrys the upper part only disappears, while the middle part forms a hair, and the 
basal cells take part in the formation of the base of the conceptacle. In Ascophyllum 
the initial cell is persistent as a whole, and grows out into the conceptacle, divides up, 
and gives rise to a kind of placenta, which bears the sexual organs. In the case of the 
vegetative conceptacles of Turbinaria I have so far traced -their development as to be 
SECOND SERIES.—BOTANY, VOL. III. 21 
