Dr. Kuhn, in the article above referred to, gives a list of 44 genera including species which bear flowers of this kind. To this list I have added some genera, and the authorities are appended in a footnote. I have omitted three names, from reasons likewise given in the footnote. But it is by no means easy to decide in all cases whether certain flowers ought to be ranked as cleistogamic. For instance, Mr. Bentham informs me that in the South of France some of the flowers on the vine do not fully open and yet set fruit; and I hear from two experienced gardeners that this is the case with the vine in our hothouses; but as the flowers do not appear to be completely closed it would be imprudent to consider them as cleistogamic. The flowers of some aquatic and marsh plants, for instance of Ranunculus aquatalis, Alisma natans, Subularia, Illecebrum, Menyanthes, and Euryale, remain closely shut as long as they are submerged, and in this condition fertilise themselves. (8/2. Delpino ‘Sull’ Opera, la Distribuzione dei Sessi nelle Piante’ etc. 1867 page 30. Subularia, however, sometimes has its flowers fully expanded beneath the water, see Sir J.E. Smith ‘English Flora’ volume 3 1825 page 157. For the behaviour of Menyanthes in Russia see Gillibert in ‘Act. Acad. St. Petersb.’ 1777 part 2 page 45.--On Euryale ‘Gardener’s Chronicle’ 1877 page 280.) They behave in this manner, apparently as a protection to their pollen, and produce open flowers when exposed to the air; so that these cases seem rather different from those of true cleistogamic flowers, and have not been included in the list. Again, the flowers of some plants which are produced very early or very late in the season do not properly expand; and these might perhaps be considered as incipiently cleistogamic; but as they do not present any of the remarkable peculiarities proper to the class, and as I have not found any full record of such cases, they are not entered in the list. When, however, it is believed on fairly good evidence that the flowers on a plant in its native country do not open at any hour of the day or night, and yet set seeds capable of germination, these may fairly be considered as cleistogamic, notwithstanding that they present no peculiarities of structure. I will now give as complete a list of the genera containing cleistogamic species as I have been able to collect.