190 Lloyd Williams. — Studies in the Dictyotaceae . 
prodigious numbers produced, and yet so far as the production of new 
plants is concerned nearly the whole of the energy expended and the 
elaborate mechanism employed has been wasted. This, of course, is an 
old story, but every new exemplification of it comes with a fresh surprise. 
The antherozoids were described by me in a short paper published 
in 1897. Since then I have had many opportunities of examining these 
bodies in the active condition, of fixing and staining them by better 
methods, and of studying their structure by means of superior objectives. 
Some of the conclusions first arrived at are now found to be incorrect 
in certain particulars, and several points which were then obscure have now 
been satisfactorily cleared up. 
Taking first the antherozoid as it appears in the living condition, we 
find that it is pear-shaped while active, but spherical when it comes to rest 
(Fig. 18). At the broader, posterior end there is a globular colourless part 
which with chromatin stains takes on an intense colouration, showing it to be 
the nucleus. The pointed end is occupied by granular protoplasm in which 
there is always a very minute red eyespot, sometimes two as in the lowest 
example in the figure. Instead of being situated close to the attachment 
of the cilium as is usual in other antherozoids and in zoospores, the eyespot 
here is always at a distance from it, frequently at the pointed anterior end. 
The cilium is not terminal as was stated in the ’97 paper, but lateral as 
in other Phaeophyceae ; this fact can be clearly seen only while the anthero- 
zoid is in motion. The cilium is attached at the posterior edge of the 
cytoplasmic cone, near its junction with the nucleus. Very often there 
seems to be a slight thickening at the very base, but on this point it is not 
easy to speak with certainty. 
Of the fixed preparations one of the most successful is that shown 
in Fig. 1 5, fixed with potassium-iodide iodine in sea- water ; this preserves 
the form and structure very faithfully. Those in Fig. 16 were fixed in 
dilute Flemming solution, and stained by the iron-alum method. Here 
the anterior part is much wrinkled, but the nuclei and physodes are very 
distinct. When fixed with dilute Hermann’s solution (Fig. 17) and stained 
with gentian violet the nuclei stain very deeply, the cytoplasm slightly, and 
occasional physodes are seen. At the upper right-hand corner is shown 
a monstrous antherozoid with two nuclei. If doubly stained with brazilin 
and Hoffmann’s blue the nucleus takes on the red colour, while the anterior 
part stains blue. 
The number of physodes present varies greatly, as also does their 
reaction to a solution of vanillin in HC 1 . When fresh plants are tested 
with the above reagent the sori frequently give no trace of the red colour 
(phloroglucin ?) usually given by the physodes of mature cells. At other 
times every sorus is coloured a deep red ; this happens generally when 
there has been some delay in the liberation of the antherozoids. When 
