NOTES ON RECENT RESEARCH. 



263 



immersed in the external one. A similar state of things to that now 

 described is said to be characteristic of the so-called Californian Navel 

 Orange. This apparently originated as an isolated sport, as the trees in 

 California are said to have been all propagated from one which is still 

 preserved at Washington." Fruits of the Navel Orange were recently 

 brought to the present writer, who found that the additional carpels were 

 quite at the top of the fruit, not actually protruding, but showing suf- 

 ficiently to be suggestive of term applied for a name. The author of the 

 note says that " A. P. de Candolle regarded the rind of the Orange as 

 developed from the torus or receptacle, which is usually regarded as an 

 axial structure ('Organographies vol. ii., p. 41), and Masters ('Teratology,' 

 p. 75) favours this view. In the case now figured the external rind had 

 been removed before it came to my hands. The carpels are united below 

 to the prolonged axis, but are separated above to leave an open pit, at the 

 bottom of which is the secondary fruit. The ventral surface of the 

 carpels is clothed with the characteristic glandular ' rind.' This is shown 

 in section in fig. 5, where the glands are unusually prominent and 

 crowded together in groups with little intervening tissue. In such a 

 position the ' rind ' could hardly be an axial structure. The secondary 

 fruit is shown in section in fig. 6, except that the number of carpels is 

 fewer than ordinary ; there is no deviation from the normal structure. 

 Fruits with one series of carpels may be regarded as reductions from a 

 more generalised multiseriate type. The interest of a case such as I 

 have described is the proof that a tendency to revert to the more generalised 

 type may still be latent." — E. I. L. 



Variety of Methods of Opening of Capsules. 



Orchid Capsules, Opening* of (Beik. Bot. Gent. bd. xi., ht. 7, 

 pp. 486-521 ; 2 plates). — Herr Arthur Horowitz gives an account of the 

 mechanism of the opening of these fruits. The following types are 

 distinguished. 



1. Thunia Marshalliana. Constrictions appear along the middle 

 of the carpels through this part ceasing to develop and a longitudinal 

 slit appears. 



2. Many European forms open in three longitudinal slits on account 

 of the strains set up by the difference in contraction of the strongly 

 thickened midribs of the carpels and of their slightly thickened placental 

 portions. In the latter the rows of cells run horizontally and not 

 vertically. 



3. PajjJiiojJedilum, &c, differs in having one or two special rows of 

 cells which facilitate the splitting. 



4. Also similar, but with several rows of cells (Bulbophpllum sp.). 



5. Special rectangular masses of thin-walled cells separate the inner 

 epidermis from the sterile valves and assist in the opening. (Coeloyyne sp., 

 Epidendrum sp.). 



6. Strong fibre cells, which are unable to contract longitudinally, 

 are formed on both sides of each of the six vascular bundles. Thus slits 

 appear at each of these rows of fibre cells (Pleurothallis). Hygroscopic 

 hairs on the inner surface of the placental region appear to distribute the 



