Cefatopteris thalictroides , (L.) 99 
The first roots which are formed in a young plant do not 
arise from the base of the petioles, but directly from the 
stem ; their connexion with the latter will, however, be dealt 
with later. 
Goebel 1 , in his Biologische Schilderungen,’ has given a 
short account of the differences which he observed between the 
young floating and the young rooted plants of Ceratopteris . 
He found young swimming plants in British Guiana, and 
these, he states, were very different in appearance from the 
young plants which, instead of floating freely in the water, 
were rooted in the mud. The leaves of the young swimming 
plant are, according to his observations, very broad and are 
spread out on the top of the water. The petioles of the 
fertile leaves are, moreover, much swollen at their bases. 
The roots are well developed, but instead of acting as fixing 
organs they hang down freely into the water in a tuft-like 
manner. I have been unable to investigate any plants of 
Ceratopteris which show these features, for I have only been 
able to examine young and mature specimens in which the 
roots are used as organs of fixation. I cannot therefore say 
whether the differences of appearance between these two 
forms of Ceratopteris , which have been described by Goebel, 
are accompanied by any marked differences in regard to 
histological and other details. 
II. Anatomy. 
A. Leaf. 
1. Petiole. In his paper on ‘Die Blattstiele der Fame,’ 
Thomae 2 gives a description and figure of a petiole and of 
a single vascular bundle of Ceratopteris thalictroides. In 
regard to the number and position of the vascular bundles 
in a section taken through a whole petiole, Thomae states 
that two rows are present. The upper row, i. e. that on the 
flattened side turned towards the stem, consists of a single 
large bundle in the centre, with two or three smaller bundles 
1 Goebel, vol. ii, p. 281. 2 Thomae, 1886, p. 151. 
