Kusano, Further studies on Aeginetia indica. 289 



appear outside the testa at the micropylar end of the seed (Figs. 

 3, 4). These are highly turgescent with abundant cell-sap. 

 Tlie nuclei are large and conspicuous, and the cytoplasm radiate 

 from them. At an advanced stage the globular cells increase in 

 number generally up to 15 approximately (Fig. 12). As can be 

 seen in Figs. 1, 2 and 6, these are not a new tissue, but only 

 the epidermal cells of the radicle, but swollen up to nearly 4 times 

 the original diameter. Simultaneously with this changes all the 

 other cells swell up more or less making the embryo much larger 

 in size; and judging from the number of cells seen in an optical 

 section of the embryo before and after germination (compare Figs. 

 2 and 6), it is very improbable that a multiplication of cells may 

 be partly concerned in the increase of the size. An accumilation 

 of starch more especially in the tissue under the globular cells is 

 perhaps connected not with the cell-division in this place, but with 

 the further development of the globular cells. 



Now follows the outgrowth of the globular cells one by one. 

 Their external wall protrudes so as to make them first conical and 

 then papillalike in form (Figs. 7, 9, 10). The outgrowths proceed 

 further until they become slender hairs growing at times up to 1 

 mm in length. The diameter of the hairs is much smaller than 

 that of the globular cells, nieasuring 38 ju on the average while 

 the latter measure generally 115 ju in diameter. Although they 

 belong morphologically to the category of trichomes, yet they are 

 not identical in structure and even in function with the typical 

 roothairs (Schwarz, 1883); they are often septate or even branched 

 (Figs. 8, 9, 14), resembling rather the rhizoids of some cryptogamic 

 plants (Haberlandt, 1904, p. 200). If undisturbed, they are all 

 straight and radiate from the radicular end in all directions as 

 shown in Fig. 8, but if one of them during its further Prolongation 

 should come in contact by its tip with a young host-root, it seems 

 to attach itself hrnily to the latter and then to coil or contract 

 through its whole length, whereby the seedling is drawn closer 

 to the host (Fig. 10). This is evidently an advantageous contrivance 

 for the parasite to facilitate its organic connection with the host, 

 that is to say, the formation of the primary haustorium. In Fig. 

 9 is shown one of the hairs just adhering to a host-root, and about 

 to bend itself, while in Figs. 10 and 12 are shown hairs in a much 

 contracted condition with the radicular end brought much nearer 

 to the host. 



By what means the tip of the hair fixes itself to the host 

 has not yet been made out exactly. It is not impossible that a 

 cementing substance is secreted by the hair, but there has actually 

 come under my Observation such a case as shown in Figs. 9 and 

 10, where the fixation was effected by a slight penetration of the 

 tip of a hair between the epidermal cells. My observations, how- 

 ever, are not extended enough to justify the conclusion that this 

 is a general case with Aeginetia. 



So far as I know, such an organ has not hitherto been 

 described in phanerogamic parasites. Analogous but not homo- 



Beihefte Bot. Centralbl. Bd. XXIV. Abt. I. Heft 3. 19 



