74 Davis . — The Fertilization of Batracho sperm u m . 
From the present trend of theories of heredity one would 
suppose the first suggested possibility very improbable. But 
the second condition would be also very remarkable indeed. 
It will perhaps be safest to defer judgement until we have 
more detailed information about the process of fertilization in 
allied forms of the Florideae and other Algae. 
University of Chicago, 
October i, 1895. 
EXPLANATION OF FIGURES IN PLATES 
VI AND VII. 
Illustrating Mr. Davis’ paper on Batrachospermuni. 
All figures sketched with the Camera lucida. 
PLATE VI. 
Batrachospermuni moniliforme , Roth. 
Figs. 6-18. Drawn from specimens fixed in absolute alcohol and stained with 
Mayer’s acid haemalum, glycerine preparations. x 2400. 
Fig. 1. Procarpic branch with very young trichogyne developing from carpo- 
gonium-cell (c), stained with Mayer’s acid haemalum. x 2400. 
Fig. 2. A trichogyne drawn from life, showing distribution of chromatophore- 
derivative, x 1600. 
Fig. 3. A group of antherozoids (lettered a, b, and c ) in different stages of 
development, illustrating the gradual change that takes place in the chromatophore 
as the structure matures. Drawn from life. x 2400. 
Fig. 4. A group of developing antherozoids, stained with Mayer’s acid haema- 
lum. xifioo. 
Fig. 5. An old trichogyne, showing the chromatophore-derivative as it appears in 
this structure and in the two antherozoids at the right and left, x 2400. 
Fig. 6. Trichogyne united to carpogonium ; nucleus of antherozoid at further 
side of that structure. 
Fig. 7. Antherozoid at the left fused with the trichogyne; that at right merely 
applied against the cell- wall ; cell-contents of trichogyne about to separate from 
the carpogonium. 
