DEVELOPMENT OF THE CEPHALOPODA. 37 
of hyphe or apothecia. Of course small portions from 
various places in a tuft of any given alga could be previously 
well examined, which, though if indeed found to represent 
the alga “ pure and simple,” would not render it absolutely 
conclusive that some other portion of the tuft might not 
already have been invaded by the “parasite.” However, 
having selected some plants for experiment, they should be 
well inoculated with spores and portions removed from time 
to time for examination and experiment. If found satisfactory 
it would be interesting to try spores from the same and from 
different species (as, for instance, such as fig. 5 and fig. 26, or 
fiz. 2 and fig. 19) in order to see the result, and whether the 
apparent fixity of the forms and the apparently extreme 
exclusiveness of the “ parasites” be true or not, or ultimately 
whether the theory be true itself or not. Whether, for the 
time being, the truth of the new theory be previously assumed, 
or its untenability be presupposed, would matter very little, 
if the suitable opportunity and ready field of operations were 
at command of the observer. It would seem as if in this 
way only can either presupposition be justified or negatived. 
Pending the ultimate decision at which the great lichenists 
who are at work on the broad question may arrive as to the 
true nature of these interesting plants, and pending too the 
discovery of the spermogonia of the forms here referred to as 
assisting to throw a light on their mutual affinities and rela- 
tive position, I may well leave to more skilled hands the 
desultory notes brought forward in this communication 
touching their general bearing and ultimate application as 
regards one of the most interesting and problematic botanical 
questions of the day. 
OBSERVATIONS on the DEVELOPMENT Of the CEPHALOPODA. 
By E. Ray Lanxester, M.A., Fellow of Exeter College, 
Oxford. (With Plates IV and V.) 
W orRKERS are so numerous and so energetic at the present 
moment in the field of embryology that a man who has there 
gathered something new after some labour, must hasten to 
publish his results, even though in a rough and incomplete 
form, if he would have them serve as contributions to know- 
ledge. Elaborate illustrations require for their preparation 
so great a lapse of time that before they can be issued some 
other observer has likely enough given to the scientific public 
