on the Saprolegnieae. 207 
tomitus) corcagiensis , as in other species of Saprolegnia and 
Achlya . 
At the period of this ‘ rotation 5 (as I hold it) there appear 
clear spots free from granules in the centre of each origin, 
near the sporangial wall ; these Rothert interprets as nuclei, 
though he has failed to stain them. I have succeeded once in 
so doing in Achlya with Draper’s dichroic ink, a logwood stain. 
In a long discussion Rothert insists on these origins being 
simply ‘ Anlagen,’ and united by the uninterrupted ‘ Wand - 
beleg' of granular protoplasm ; and discusses Biisgen’s 4 Korner- 
platten,’ which he shows rest on a confusion between the 
plasmatic threads often uniting the origins, and the fact that 
there is usually an accumulation of coarse granules on the 
whole of the convex half of the origins, a point to which I 
have also drawn attention. 
He ascribes the errors of his predecessors to unsuitable 
objects for research, to the use of insufficient powers, and 
the influence of preconceived ideas derived from the con- 
sideration of the embryo-sac. I may mention that Dr. Biisgen 
has written to me that this last was actually the case with 
himself. Of course these facts and considerations do away 
with the hypothetical gelatinous £ Zwischen-substanz,’ which 
is only the expression of the £ Wandbeleg ’ between the 
origins. 
This description of the stage of preliminary segregation 
is essentially the same as mine, completed however by the 
observation of the plasmatic threads joining the £ origins/ 
which I have verified and accept. I have adverted to one 
error of interpretation in these preliminary processes. 
The origins now contract, widening the interspaces and 
breaking most of the plasmatic threads, and at the same time 
become smooth on their free surfaces which before were rough 
and granular. In this stage Rothert has seen the ‘ rotation 5 
and change of place I have before adverted to. This stage 
lasts at most one or two minutes, to give place to Biisgen’s 
£ homogeneous stage , 5 which Rothert calls the stage of swelling 
up of the spores. The origins swell up, touch, and apparently 
