296 Scott and Brehner. — On the Anatomy 
however, are quite indecisive, and he admits himself that he 
could not obtain much information from the dry material he 
examined 1 . 
De Bary’s investigation of the malpighiaceous Dicella 2 was 
also made on dry material. He comes to the same conclusion 
here as in Strycknos, but a re-investigation is obviously 
required. 
Passing over several groups mentioned by Solereder, but of 
which we have no detailed knowledge as regards the point in 
question, we come to Salvadoraceae, an order not so very 
remote from the Loganiaceae. The phloem-islands of Salva- 
dora have been thoroughly worked out by Kolderup-Rosen- 
vinge 3 , and we have been able to confirm his statements. In 
this very interesting plant, which in habit resembles a fruticose 
Strycknos , the phloem-islands are even more numerous than 
in that genus, and occur not only in the stem, but in the root 
and in the petiole of the leaf. The primary bundles, however, 
are not bicollateral. In the stem the islands resemble those of 
Strycknos , but contain rather more parenchyma. There is 
no doubt that they are formed centrifugally on the inner side 
of the normal cambium, and thus form morphologically a part 
of the wood. After an island is developed the same cambium 
resumes xylem-formation outside it, and so the phloem be- 
comes imbedded. In fact, the process which de Bary erro- 
neously supposed to occur in Strycknos , actually takes place 
in Salvadora. After the phloem is imbedded irregular cambial 
divisions go on, both towards the outer side of the island 
and elsewhere, and a certain amount of obliteration takes place 
towards the centre of the group. The external phloem here 
is well developed. 
I11 the root the structure is different. Here the islands con- 
sist chiefly of parenchyma. They are of large extent, and are 
often irregularly confluent with one another, as seen in trans- 
verse section. It appeared to us that the formation of the 
1 1. c. p. 187. 2 1. c. p. 580. 
3 Anatomisk Ondersoegelse af Vegetationsorganeme hos Salvadora , in Oversigt 
K. Dansk. Selskabs, 1880-81. 
