472 OPHIOGLOSSALES 
under ‘side. Hitherto only a preliminary account of this strange anomaly 
within the genus Bofrychium has been published, and it will be necessary 
to await the detailed description which will 
supply the materials for an exact comparison. 
But meanwhile Mr. Lyon has most generously 
lent slides showing not only some advanced 
stages, but also the earliest stages of embryo- 
geny, from which the following facts and 
drawings have been derived.1 Transverse 
sections of an embryo corresponding to that in 
Fig. 264, showed the suspensor (s), cotyledon 
eo 
(cu asE to). eomuledenss cae Positions ascribed to them by Lyon, and 
sensor: From a preparation lent by H. demonstrated the correctness of his interpre- 
tation of the longitudinal section (Fig. 265). 
But what is more important is that sections traversing archegonia, shortly 
after fertilisation, showed that the zygote, while still undivided, grows 
Fic. 265. 
Fic. 266. 
Botrychium obliquum. First stages in the embryogeny ; before the first segmentation 
the zygote grows into an elongated tube (the suspensor), which burrows its way 
irregularly into the tissue of the prothallus. Xz50. From sections lent by H. Lyon. 
into an elongated tube, which takes an irregular course downwards into 
the tissue of the prothallus (Fig. 266); its nucleus settles down to the 
1Mr Lyon’s action in this matter deserves special recognition. When circumstances 
delayed the completion of his own statement, knowing the importance which the main facts 
bore in embryological comparison, he forwarded a set of slides to me in Glasgow, with 
permission to use the facts they showed in whatever way I found necessary. F. O. B. 
