478 Harper. — Cell- Division in Sporangia and Asci . 
numerous nuclei which appear prior to sporangium-formation. 
In assuming the existence of direct division here he confirms 
the observations of Rosen \ who finds that the nuclei of 
S. Taraxaci regularly divide directly, and not by karyokinesis. 
Dangeard, to be sure, thinks karyokinesis occurs in some 
cases, but his figures give little evidence that he had really 
seen mitotic figures. Dangeard describes the division of the 
primitive cell to form sporangia as a process of simultaneous 
fragmentation, whereby the multinucleated mass is at once 
cut into a larger or smaller number of polyhedric multi- 
nucleated portions. These are the sporangia. They become 
enclosed in a membrane, round themselves up, and later the 
zoospores are formed equalling in number the nuclei in 
the sporangium. 
Dangeard notes merely this simultaneous fragmentation 
of the protoplasmic mass. The portions are separated from 
each other by a layer of colourless protoplasmic liquid. 
Very recently C. M. L. Popta 2 has studied spore-formation 
in several of the so-called group of the Hemiasci, with 
special reference to the comparison of the phenomena in 
these forms with those in the ascus and in the sporangia of the 
lower Fungi. According to Popta, the process of delimiting 
the spores in Ascoidea rtcbescens is initiated by the appearance 
of abundant vacuoles in the protoplasm. These vacuoles are 
separated from each other by numerous protoplasmic plates 
and threads. This reminds us of the condition in Pilobolus 
as I have described it further on, but according to the author 
these angular vacuoles, instead of cutting through the plasma- 
plates and fusing edge to edge to divide the plasma into 
spore-masses, gradually become rounded up and disappear. 
The protoplasm now becomes charged with oil drops and 
granules. Later, hyaline non-granular protoplasm begins 
to gather round the nuclei, and these non-granular plasma- 
masses become delimited by membranes and, ultimately, uninu- 
cleated spores. Almost at once the single spore-nucleus 
1 Cohn’s Beitr. zur Biol. d. Pd., Bd. vi. 
2 Beitrag zur Kenntniss der Hemiasci, Flora, Bd. lxxxvi. pp. 1-46, 1S99. 
