4B8 Harper . — Cell- Division in Sporangia and Asci. 
The changes which take place in the process of cleavage of 
the protoplasm into the swarm-spores I have not as yet been 
able to study. The functional analogy between the nuclear 
divisions and growth of the protospore which takes place in 
the mother sporangium and the development of the egg in 
the tissues of the parent in the higher plants is sufficient to 
justify the distinction of an embryonic stage in the life-history 
of the fungus. 
In Synchitrium Taraxaci this whole process of cleavage is 
abbreviated by the omission of the protospore stage. The 
multinucleated segments formed by the first cleavage-furrows 
round up, their nuclei become still more numerous by division, 
and they are then set free at once and germinate as sporangia. 
The life-history of the fungus is thus much shorter, and it is 
able to spread with great rapidity when conditions are 
favourable. As is known, provision is made in this species 
for its existence during unfavourable periods by the formation 
of the so-called resting spores. The relation between the 
cleavage processes in ^S. decipiens and .S'. Taraxaci is the same 
as that between the segmentation in Pilobolus and in Sporodinia , 
as we shall see later. 
The question arises whether the protospore or the swarm- 
spore is the homologue of the gamete in the higher plants, but 
the resemblances are too remote, and the probability of any 
genetic relationship between these particular lower forms and 
the higher plants is too slight, to justify any speculation on 
this point. If we now summarize the life-history of the fungus 
we can roughly, and for purposes of comparison with other 
forms, distinguish five stages. 
1. The multiplication of the nuclei by which the uninu- 
cleated vegetative body becomes multinucleated as a pre- 
paration for the formation of a corresponding number of 
reproductive bodies. 
2. The progressive cleavage from the surface inward of the 
multinucleated mass into uninucleated masses or protospores. 
These two processes constitute the original and fundamental 
elements in spore formation. 
