TO THE KNOWLEDGE OF PLATYZOMA MICROPHYLLUM. 
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All the sporangia on several plants have been examined, and the size and form 
of the sporangia, and the spore size and output per sporangium, have been deter- 
mined in 1000 cases. Of these sporangia 890 or 89 per cent, were small, 110 or 
11 per cent, were large. The largest number of sporangia observed on a pinna was 
11, the smallest 5. When the number of sporangia per pinna was large the 
majority of the sporangia were small. Thus of the 11 sporangia in one pinna 
10 were small, 1 was large. When the number of sporangia per pinna was small 
the large sporangia were usually more numerous. The largest number of large 
sporangia observed in any pinna was 3, and there was an accompanying reduction 
in the number of the small sporangia out of all proportion to the increase in number 
of the larger forms. Thus one pinna contained 2 large and 3 small sporangia. The 
majority of the pinnae bore both small and large sporangia. In some cases only small 
sporangia were present, but in no pinna were large sporangia alone developed. 
Typical views of small sporangia are shown in text-figs. 4, 5, and 6. The stalk 
is short and the globular capsule is commonly lopsided. The annulus is variable in 
position and is typically irregular: It usually begins at the back of the stalk, and 
passes obliquely over the top of the capsule. There is a well-defined stomium. 
The most regular annulus observed is depicted in text-fig. 7. The sporangium 
