130 LIVERPOOL BIOLOGICAL SOCIETY. 
have referred to all deal with the subject of cross- and 
self-pollination—a very different matter. The wider and 
more fundamental problem indeed cannot be answered 
until investigations have been made in this relation on the 
phenomena of fertilization among the Cryptogams. 
Generally speaking it may be said that cross-fertilization 
is at least possible in all cases where motile male cells are 
formed; where, on the other hand, as in the majority of 
Fungi and not a few Alge, the male element is not motile 
and 1s produced in close proximity to the female organ, 
self-fertilization seems alone possible. Perpetual self- 
fertilization, 1t 1s interesting to note, has apparently had 
no ‘‘injurious”’ effect in such close breeding forms as 
Hurotium, Phytophthora,—forms which are amongst the 
most vigorous and widely distributed Fungi with which 
we are acquainted. 
Experiments may show that no universal law can be 
laid down, but that for each group, perhaps for each genus 
or even species, one or other condition is the more effica- 
cious—in other words, that in attempting the solution of 
this as in so many other problems, we are driven back to 
the consideration of the physiological and morphological 
properties of protoplasm, the elucidation of which has 
been well termed the supreme problem in Biology. 
