Origin of ‘ Transfusion Tissue \ 977 
with aniline sulphate. Microtomed sections lent by Mr. Hill were also 
looked through for comparison. 
Preparations were made of each of the following species: Taxus 
haccata, Cepkalotaxuspedunculata , C. Fortunei, Araucaria brasiliensis, Pinus 
sy Ives iris, Sequoia sempervirens, Sciadopitys verticillata , Cupressus Law - 
soniana , C. tortulosa , Thuja orientalis , 7 ". spheroidea , and Juniperus com¬ 
munis. 
Microtomed sections of these and of Podocarpus chinensis were also 
examined. 
The work was undertaken without immediate reference to the litera¬ 
ture, and the following questions were kept in view throughout:— 
1. When very little transfusion tissue is present, e. g. at the tip of the 
cotyledon, is it on the adaxial side of the bundle or does it form the 
‘ wings ’ referred to by Haberlandt ? 
3 . Is it ever more abundant on the adaxial side than towards the 
flanks of the bundle ? 
3. Is there any proportion to be observed between the amount of 
centripetal xylem and of transfusion tissue in a cotyledon ? 
The following observations were made:— 
1. Taxus baccata, Linn. In some cotyledons no transfusion tissue was 
found. The earliest beginning of it which was noted was a group of two 
(soon increasing to three) elements prolonging the incipiently crescent¬ 
shaped mass of xylem at one of the horns. At that level no centripetal 
xylem was present, though a single element in an almost median position 
occurred lower down. 
2. Cephalotaxus pedunculata , Sieb. and Zucc. Transfusion tissue begins 
in the adaxial position. In one case a transfusion tracheide was present 
before centripetal xylem was formed. It is not contiguous with the pro- 
toxylem, and is larger than any of the xylem elements, though there is 
not the great disproportion in size that is seen in some other genera. 
3. C. Fortunei differs from the above in having much less transfusion 
tissue. The beginnings were not observed. 
4. Podocarpus chinensis. A single microtomed series was available. 
Transfusion tissue began with a single element of large size similar in 
position to that of Taxus , in both bundles of one cotyledon, and in the 
other it was also first formed at the side ; though the shape of the xylem 
here was less regular. 
5. Araucaria brasiliensis proved to be one of the most difficult species 
to investigate. The transfusion tracheides were not very numerous, were 
more difficult to distinguish from the xylem than in some other forms, 
and showed no constancy of position with regard to it. Sometimes two 
or three arose at the side of the bundle; once at least the first one came 
on the ventral side, which is unique amongst all the cotyledons examined. 
