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without having recourse to the inside coating of glycerine which 
makes them so unpleasant to handle. The specimens are then ready 
for sectioning in an hour’s time. 
Hard paraffine if melted over several times before being used for 
imbedding will cut very much better than that taken directly from 
the new cake. But the greatest care must be taken not to let it get 
too hot by letting the temperature rise too much above the melting 
point. 
The attempt to use xynthol instead of absolute alcohol resulted in 
failure, for material in good condition up to the time of transference 
to a xynthol solution became so shrunken and dried that it was worth- 
less. Neither did xynthol work well in dehydrating the slides in the 
process of staining. 
In regard to the stains that were used, Delafield’s haematoxylin 
was found to be most satisfactory for antheridia and archegonia and 
Fleming’s triple stain of saffranin, gentian violet and orange G for the 
later stages. For this work over forty different collections of Pellia 
epiphylla have been made, the number for each month depending upon 
the activities of the plant, seven collections being made in June, 
against one each in the months of December, February and March. 
These different collections will now be considered in order, be- 
ginning with the earliest date on which the new season’s growth was 
found. 
April 15 one of the best collecting grounds of the city was vis- 
ited. Here within the space of a few feet quite a variety of stages 
was found. The plants on the bank a few feet back from the river's 
edge were dried down and the sporogonia hardly protruded from 
under their protecting membranes. On a tussock directly over the 
water was a mass of plants with sporogonia that had pushed up on 
stems an inch or more in length with capsules that seemed just ready 
to open. Others had already opened and had shed their spores, only 
the brown tufts of fixed elaters at the center of the base of the capsule 
being left. Between these extremes of dry and moist conditions the 
sporogonia were found in various stages. Some were just ready to 
shed their spores, others had pushed up only a short distance, others 
were just protruding beyond the involucre. Those whose stems 
seemed to have grown to full height, or whose spores had been dis- 
charged showed a thallus much reduced. Generally nothing was left 
of the old plant but a thin narrow band, dark brown in color, and the 
sporogonium instead of being some distance back from the growing 
point now seemed to beat the very tip of the thallus (Figs. 7a, 7b). 
New bright-green shoots, more or less folded and curved, were to be 
seen springing out from the edges of the old plants which seemed 
about to die down and disintegrate (Figs. 2, a, b, c, d, e). 
The next collection was made on April 21, at the same place. 
Almost exactly the same variety of stages of sporogonial development 
