290 Kusano, Further studies on Aeginetia indica. 



logous cases may perhaps be found in the root-hairs that develop 

 previoüs to the formation of haustoria on the typical root of some 

 hemi- and holo-parasites, such as Melampyrum (LeclercduSablon, 

 1887), Lathraea (Heinricher, 1895, p. 381), Santalum (Barber, 

 1906). In all these cases the root-hairs appear to serve simply 

 for the fixation of the root of the parasite to the host. The 

 cushion-cells in Cuscuta (Peirce, 1893) may be considered to 

 perform the similar function. In Aeginetia it is quite obvious, as 

 already stated, that the hairs serve first of alias a „tentacle", and 

 after contact with the host, as a „prehensile organ", besides drawing 

 the seedling closer to the host. In function, therefore, they possess 

 all the characters of a typical tendril (i. e., Oucurbitaceae), and 

 hence I venture to propose for them the name of „hair-tendrils". 

 In the root-system a similar function has already been known 

 to appertain to the so-called root-tendrils (see Pfeffer, 1904, 

 p. 416). They are not, however, identical morphologically with 

 the hair-tendrils; for in typical root-tendrils the entire root plays 

 a part of a tendril, while in hair-tendrils an appendage of the 

 radicle c@mes into play. In origin, again, the hair-tendrils may 

 be homologous to the papilla-like cells at the tip of the radicle 

 in the seedling of Orobanche (Koch, 1883, p. 189). However, in 

 structure and function the latter organ seems to be different from 

 the former showing a rather close resemblance to the cushion-cells 

 of Cuscuta. 



The kind of Stimuli required in causing the curvature of the 

 tendrils remains still unknown. But on the basis of my culture- 

 experiments it seems highly probable that, unlike the true root- 

 hairs (see Pfeffer, 1904, p. 459), mere contact with sand- or 

 soil-particles remains quite ineffectual, but that some chemical 

 Stimulus must be concerned, to which the tip of the tendrils coming 

 in contact with the host-root must respond. That normal tendrils 

 may respond to chemical Stimuli has already been ascertained by 

 Correns (1896, p. 16). 



In almost all cases the globular cells do not appear to develop 

 all into the hair-tendrils: some of them remain unchanged, while 

 some are arrested from further development after reaching the 

 conical or papillae stage. As for the most probable ground of 

 such variable development of the globular cells, my observations 

 of a number of seedlings have led nie to the conclusion that the 

 number of tendrils that are formed in a seedling must depend more 

 or less upon the chances of meeting with an appropriate host. 

 In fact I have found that when a seedling came on contact with 

 a host by a premature development of some tendrils the remaining 

 ones were more or less arcested from further development and the 

 globular cells from forraing further tendrils (Figs. 9, 10, 12); while 

 when a seedling remained away from the host long enough many 

 tendrils were observed to develop at once and in füll length, or 

 many globular cells to give rise to tendrils (Fig. 7). This fact 

 makes it most probable that the seedling develops as many tendrils 

 as possible in several directions until it finds out a host thus 



