Raspberries on a bifurcate thalamus
Recueil des travaux botaniques néerlandais , Volume 6 - Issue 1 p. 63- 66
In Yol. IV, p. 145 of the present Receuil I had an opportunity of drawing attention to specimens of Rubus idaeus, of which the fruits covered a bifurcate thalamus. I pointed out that the thalamus quite gave the impression of having subsequently split up and not of having been dichotomous from the outset as Godron admitted for his cases. At the end of my paper I had to forego a decisive explanation of my case, owing to the origin of the fruits in question being unknown. Since that time, however, I have had the good fortune to discover the origin of the monstrous raspberries, viz. a garden at Hilversum, called „de Proeftuin” and founded by the „Maatschappij voor Tuinbouw” with a view to cultivate various kinds of fruit and vegetables. In order to test Go dr on’s statement according to which dichotomy of the torus is the primary cause of the above-mentioned phenomenon, I thought if best to collect raspberries in subsequent stages of development and possessing an augmented calyx and did so on June 20 and 27, July 4 and 15 and September 8. The number of specimens collected amounted to 15, 8, 18, 6 and 2 in the same order as the dates. All these fruits have been carefully examined and have furnished only one receptacle of which the top was dichotomous. As is shown in fig. 1, which represents this torus slightly magnified (the edible part of the fruit having been removed) the whole surface was covered with carpels and could not have been anything but an.entire thalamus growing in two directions. The number of carpels amounted to 150, whereas the ordinary number seems not to exceed 100. The calyx is made up of six sepals, a fact noteworthy in itself, since it shows augmentation also in this respect. On the other hand there were 40 specimens possessing quite simple receptacles and showing not even a trace of doubling.
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