8o 



HARDWICKE'S SCIENCE-GOSSIP. 



lamina of mischief below. On turning the leaf over, 

 round orange-coloured spots will be observed scattered 

 over the leaf, and in some cases affecting the petiole. 

 The central peridia are abortive. Most of these 

 points can easily be distinguished with the naked 

 eye. 



Dr. Cooke's description is as follows : CEcidium art, 

 Berk. ; wake-robin cluster cups ; spots round, con- 

 fluent ; peridia circinative, not crowded, central ones 

 abortive. 



The whole plant seems to exist very comfortably 

 even when severely affected with this fungus. Many 

 of the unhealthy plants of arum I have examined this 

 season have been entirely free from the CEcidium, 

 though in company with numbers affected. The 

 plants in this part of the country are only locally 

 affected, one locality only furnishing specimens. 



It is now time, I think, to pass on to the contempla- 

 tion of that interesting and curious structure, the 

 spadix. The spadix of the arum, commonly known 

 as " the flower," is well calculated to puzzle the 

 novice at botanical description. The spadix is 

 enclosed in a green spathe, considerably longer than 

 the spadix. This spathe, on opening, is sometimes 

 found to be spotted in the same manner as the leaves, 

 only the colour is brighter, and the spots have the 

 appearance of being raised above the surrounding 

 tissue. It does not follow that the plants whose 

 leaves are spotted have their spathes spotted also. 

 The spadix terminates in a naked cylindric column 

 contracted below the middle. The colour of the 

 column is dull purple, or sometimes yellow ; rarely 

 white. The shades of purple vary somewhat, but it 

 is not common to find the yellow and white varieties, 

 though I have done so several times this season. 



The column has a very velvety appearance and is 

 beautifully smooth to the touch. On examination it 

 will be found to be covered externally with minute 

 papillae, secreting colouring matter (Fig. 61). These 

 are very minute, and the best way to view them is to 

 take a very thin section of the column and view with 

 a \ or \. The column is of cellular structure with 

 every cell so closely packed with starch grains that, 

 as in the corm, it is very difficult to discern the tissue 

 of which it is composed, except in the centre through 

 which run cells with numerous air cavities ; raphides 

 can also be seen. I have noticed this year a curious 

 disease of the column which may possibly be common 

 enough, only it has never before come under my 

 notice. In numbers of cases on the spathe opening, 

 I have discovered the terminative column of the 

 spadix covered with a mould. In some instances the 

 column presented a miserable shrivelled appearance, 

 while in other cases perfect size was gained. In very 

 few cases did the diseased column affect the organs of 

 reproduction. Many of the plants noted by me as so 

 affected are now in fruit. The column showed very 

 plain signs of disease throughout its structure. If 

 picked and brought home the spadix so diseased 



gradually reached a gelatinous consistency, and 

 emitted a most offensive odour. It would be 

 interesting to have the work of some authority, on 

 the subject of this mould. Unfortunately, the time 

 is so short between the opening of the spathe and the 

 fall of the column that almost hourly attention would 

 have to be given to the matter. 



Leaving the column and descending the spadix, we 

 come first of all to a ring of organs which in reality 

 are aborted stamens or staminodes j next to these are 

 a crowd of sessile anthers. The pollen possesses no 

 special feature in markings or shape. Below the 

 anthers are a ring of rudimentary ovaries,- and lastly 

 a crowd of naked sessile ovaries. Fig. 62 shows the 



—ft, 



Fig. 61. — Papillae from the column of 

 the Spadix. (Mag.) 



Fig. 62. — Spadix 

 with the spathe 

 removed, a, ex- 

 tremity of the 

 spadix ; b, stami- 

 nodia ; c, sessile 

 anthers; d, 

 naked sessile 

 ovaries. 



spadix with the spathe removed, with the various 

 organs I have mentioned. The fruit of A. maculatum 

 is a berry, a large quantity being clustered together, 

 bursting the base of the spathe, which is persistent. 

 When ripe the berry becomes red, and should be 

 most carefully avoided by all persons having a 

 tendency to taste luscious-looking berries, or the result 

 of the repast may be alarming, if not serious. Should 

 a child be unfortunate enough to eat any of these 

 berries, an emetic should be given, and the mouth 

 should be carefully cleansed from all particles of 

 berries remaining there. 



There is one curious property connected with this 

 plant, which it would be very negligent not to mention. 

 I mean the power of evolving heat possessed by the 

 spadix on its first opening. I had hoped to give a 



