1 14 Barber. — -On a change of Flowers to 
tissues attendant on the presence of any foreign irritating 
body. 
It seems necessary, therefore, having regard to the above 
definition, to consider the change as due to some debilitating 
causes. The readiness with which Nymphaeas are affected by 
alterations in the amount of light, heat, space and soil afforded 
them has been well shown by Caspary in his experiments on 
the magnificent Nymphaea zanzibariensis. ‘ If the plant be 
grown in a tub sixteen feet square, without covering, five or 
six inches under the water’s surface, it is gigantic, with leaves 
two feet in diameter, and flowers nine inches and more across. 
If grown in a flat pan fifteen inches in diameter, the leaves and 
flowers are only half the size. While, in a pot eight inches in 
diameter, the flowers hardly reach an inch in diameter V 
The changes induced in Nymphaea Lotus are probably due 
to the introduction of the plant to our greenhouses from the 
sunlit lakes of Central Africa. It must be borne in mind, 
however, that we do not know the plant in its own home ; 
and it is quite possible that this abnormality may be not un- 
common in its native habitat. 
The plant differs essentially, as we have seen, from cases 
where the change in the flower is of no further use. We may 
rather regard the present instance as analogous to that of 
Opuntia whose fruits, when placed in the soil, grow into new 
plants, roots being developed from their bases, and shoots from 
their apices 2 . The flower is, in each case, prevented from 
ripening its seeds ; and yet, so strong is the tendency towards 
reproduction residing in the branch, that, when prevented from 
developing in the normal manner, it is able to substitute the 
probably less expensive vegetative reproduction, and thus still 
to perform its function. 
In Nymphaea the change is from the uncertain method of 
cross-fertilization and dispersal to the surer, though more 
primitive, method of multiplying by means of tubers dropped 
from the decaying peduncles into the surrounding mud. The 
1 Engl. Jahrb. iv. n 6. 
2 Morris, in Gard. Chron., 22 Sept., 1888, Fig. 43. 
