However, it is easy to observe that on lime-trees they prefer the lower
parts of each twig, while on magnolias the terminal leaves of the
branches are often pitcher-bearing. Ascidia of the white clover have
been found in numbers, in my own experiment-garden, but always in the
springtime. The thickleaved saxifrage (_Saxifraga crassifolia_) is often
very productive of ascidia, especially in [367] the latter part of the
season, and as these organs may be developed to very different degrees,
they afford fine material for the study of the law of periodicity. On a
garden-cytisus (_Cytisus candicans attleyanus_) I once had the good
fortune to observe a branch with ascidia, which ordinarily are very rare
in this species. It had produced seven ascidia in all, each formed by
the conversion of one leaflet on the trifoliolate leaves. The first six
leaves were destitute of this malformation and were quite normal. Then
followed a group of five leaves, constituting the maximum of the period.
The first bore one small pitcher-like blade, the second and third, each
one highly modified organ, the fourth, two ascidia, and the last, one
leaflet with slightly connate margins. The whole upper part of the
branch was normal, with the exception of the seventeenth leaf, which
showed a slight change in the same direction.
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