( 425 ) 



shoots were characterized by internodes of ' , mm. diameter with 

 5 — 6 deep longitudinal grooves and only 5 — 6 vaginal teeth. On 

 the other hand the youngest twigs, which had been formed on the 

 ordinary ascending older branches of the same individual, had 

 cylindrical internodes, not deeply-grooved, 3 / 4 — J mm. diameter, with 

 9 — 10 vaginal teeth. For the sake of completeness the morphologically 

 unimportant, hut physiognomically striking circumstance should be 

 mentioned, that a great number of the youngest twigs of these young 

 root-suckers were malformed at their tops to ovate or irregularly 

 formed galls, about 3 — 5 mm. long and 2 1 /»— 3 mm. thick. In these 

 galls I could generally still detect the insect which had produced 

 these malformations. It need scarcely be mentioned, that the above 

 description of the morphologically aberrant structure of the twigs, 

 refers only to normally constituted ones, and not to the pathological 

 malformations on the rootsuekers, formed from adventitious buds. I may 

 further allude to a specimen collected by Tkysmann and De Vriese 

 in 1859 — J 860 in Java? (without further indications as to locality) 

 and labelled by Miquel "Casuarina equisetif 'o lia Forst., monstrosaf" 

 This specimen, found by me in the Herbarium at Leiden, appears 

 to me to be quite similar to the one, described above, of the^ordinary 

 Casuarina montana var. tenuior Miq., with young root-suckers, partly 

 deformed by galls at the shoot-tops, the number of vaginal teeth in 

 this specimen, examine 1 by Miquel is (also in the youngest twigs 

 not attacked by galls) invariably only 6 — 7, never more. 



Summing up (and wholly leaving out of account the above- 

 described malformations due to galls) we find briefly the following: 



1. In these very young seedlings of Casuarina montana var. 

 tenuior Miq., some internodes are provided with 4, others with 

 5 — 6 deep longitudinal grooves, while the number of vaginal teeth 

 is 4—6, (never more) and in the youngest stages only 4. 



2. Very young shoots formed in Casuarina montana var. tenuior 

 from adventitious buds in the base of the trunk, had similar deeper 

 grooved internodes with 5—6 (never with more) vaginal teeth, like 

 the young seedling mentioned sub i. 



3. It appears that in the species here in question (C. mo, //ana) 

 the youngest developmental stages of the seedlings show phylogene- 

 tically older phases of development than the young shoots from 

 adventitious buds of the trunk examined above. 



4. The structure of the seedlings referred to sub 1 seems to point 

 to both Casuarina equisetifolia Forst. and.C. montana Jungh. being 

 mutants of parent forms with quadrangular internodes and 4 deep 

 longitudinal grooves, with 4 vaginal teeth. Such forms, which in my 



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