204 BOTANICAL GAZETTE [SEPTEMBER 
In 1896 WorspELL (16) discovered them in the adult stem of 
Macrozamia Fraseri Miq., giving it an appearance which recalled to 
his mind the stem of the Medullosae. 
In 1897 the same author (17) gave the name “transfusion tissue” 
to certain short, scattered tracheids with reticulate markings on 
their transverse walls, found in lateral communication with the 
bundles in the green parts of some gymnosperms. He considers this 
tissue a “direct derivative of the centripetal xylem” in the vascular 
bundles of fossils. Later in the same year (18) he recorded its 
occurrence in the cotyledons of Cycas revoluta Thunb. and in the 
leaf traces of Stangeria paradoxa T. Moore. He found that in each 
of the two cotyledons of Cycas revoluta, there are three collateral 
bundles, which may increase to five; that there may be some cel 
trifugal wood near the base of the cotyledon, but none farther out; 
that the root may be tetrarch or triarch; that girdling had not yet 
begun in the young seedling he was investigating; and that anomalous 
thickenings were conspicuous. In Stangeria paradoxa, the two coty- 
ledons have a common stalk, each is multifascicular, and the bundles 
are said to be concentric near the base. The root is triarch, changing 
to diarch near the tip. In the same paper, the two cotyledons of 
Macrozamia spiralis Miq. are said to be like those of Cycas revoluta. 
The author calls attention to the absence of anomalous thicken: 
ings in this species of Macrozamia in contrast with the mature a 
of M. Fraseri previously studied by him. In all three seedlings 
WorsDELL missed the transition from stem to root. 
In 1898 the seedling of Bowenia spectabilis Hook. was described 
by PEarson (9). He says that each of the two cotyledons has four 
to seven bundles derived from one, and that these bundles are all 
collateral with normal orientation. He is emphatic as to the collateral 
nature of the bundles, even after having examined a preparation 
Worspett’s in which the latter considered them concentric: 
the leaves the bundles are oriented normally, and the centripetal 
wood, scanty at the base, becomes more and more abundant f se 
up the petiole; but the centrifugal wood does not disappeat eee 
the pinnae. The root is tetrach or pentarch, but may reduce to triarch 
In the young material at his disposal, PEARSON found no anom 
thickenings in the root, but they were discovered later in prest 
