220 Johnson . — The Procarpium and Fruit 
secondary auxiliary cells. In kind but not in degree this 
combination of ovicell with adjacent auxiliary cells is much 
like the mode of copulation described by Schmitz in the 
Rhodomeleaceae, Rhodymeniaceae, Ceramiaceae, etc. 
In carrying out this investigation of the female apparatus of 
Gracilaria , I was constantly on the watch for phenomena at 
all comparable with those found by Thuret and Bornet in 
Dudresnaya and Polyides 1 , by Berthold in the Crypto- 
nemiaceae 2 , by Schmitz in the Squamarieae 3 , and by Solms- 
Laubach in the Corallinaceae 4 . Each fruit was however 
found to be the direct product of a procarpium, and each pro- 
carpium gave one cystocarp, and one only. Still, from one 
point of view, Gracilaria shows a combination of the salient 
features exhibited in the production of the many connected, 
scattered fruits of the Cryptonemiaceae, and of the single com- 
pound fruit of the Corallinaceae. In describing the parts in 
Gracilaria , I have, as far as possible, used the terms (and with 
the same meaning) proposed by Schmitz 5 and adopted by 
Berthold. In Gracilaria the fertilised ovicell fuses with the 
rest of the procarpial cells, the auxiliary cells, homologous 
with the single auxiliary cell of, say, Gloeosiphonia ; the pla- 
cental cells correspond with the isolated fertile auxiliary cells, 
from each of which by contact with the connecting f tubes 5 a 
fruit is formed in the Cryptonemiaceae and Squamarieae. In 
Gracilaria , owing to the concentration of the auxiliary cells 
(placental cells) round the procarpium, there is no need of 
these long cellular connecting-tubes, and they are replaced by 
the protoplasmic protrusions mentioned. The formation of a 
single compound fruit in the Corallinaceae as a result of the 
fusion of a group of procarpia, only some of which are fer- 
tilised, is not unlike the formation of the single complex fruit 
of Gracilaria as the product of the more or less intimate fusion 
1 Thuret and Bornet, Etudes phycologiques, pp. 73-80. 
2 G. Berthold, Die Cryptonemiaceen des Golfes von Neapel, 1884. 
3 F. Schmitz, op. cit. on page 219. 
4 Solms-Laubach, Fauna u. Flora des Golfes von Neapel, 1881. 
5 F. Schmitz, 1 . c., p. 223. 
