SCIENTIFIC COMMITTEE, DECEMBER 9. 



CCV 



exhibited, the main roots were perfectly sound, and he could suggest no 

 cause for the appearance of the roots on the leaves. 



Xephrolepis tubcrosa. — Mr. Saunders exhibited some of the tubers 

 found on the roots of this plant. They did not appear to have "eyes" 

 or buds upon them, so as to be propagative. It was suggested that their 

 use may be for water storage only. 



Celeriac Diseased. — Specimens were sent by Mr. Kitson, The Chantry, 

 Netherbury. Dr. Cooke, V.M.H., undertook to examine and report upon 

 them. 



Hyacinth Bulbs Diseased. — Mr. Saunders gave the following report 

 upon the bulbs sent to the last meeting : — " The bulb contained a large 

 number of the bulb-mite, Bhizoglyphus echinopas, and these mites were, 

 no doubt, the cause of the injury to the bulb. Besides the mites, there 

 was a quantity of a greenish mould, which I imagine only began to grow 

 on the bulb after it had been killed by the mites. When bulbs are thus 

 infested with mites, nothing can be done to save them. When only a 

 few mites are at the base of the bulb, where the attack generally 

 commences, they may be killed by immersing the bulbs for five minutes 

 in water at a temperature of 115° or 120° Fahr. If some sulphide of 

 potassium (6 ozs. to a pint) be added to the water, this remedy would be 

 all the more efficacious ; indeed it is said that soaking the bulbs in this 

 solution cold for twenty minutes will kill the mites. It is very essential 

 that any of the soil from pots which has contained bulbs infested by this 

 pest should not be allowed to get mixed with fresh soil on the potting- 

 bench or elsewhere." Dr. Cooke added : — " There is such a profuse crop 

 of saprophytic moulds, as Penicillium, that they effectually mask the 

 disease, whatever it may be, and there are numerous Acari present." 



Dictamnus Fraxinella. — Mr. Bowles referred to the germination of 

 the seeds of this plant, as they were sown as soon as ripe, but did not 

 germinate. The Rev. W. Wilks observed that the seeds of Dictamnus will 

 not germinate if kept any time out of the ground, and added that the best 

 method with all suchlike seeds which germinate w r ith difficulty is to sow 

 them at once, the same day they are gathered, in a pan with a tile over 

 it touching the earth, and leave the tile on all through the winter and 

 well into the spring. Then if it be removed the seeds will generally 

 quickly spring up. 



Physiological Experiments. — Professor Henslow described an experi- 

 ment he had carried out with two objects in view. 



The first was to ascertain if darkness had any effect upon the direction 

 of growth of roots. He grew some Mustard on a perforated tin over a 

 glass of water, the latter having black paper pasted all over it, excepting 

 a narrow strip facing the light, which could fall upon the roots in the 

 water. They, how T ever, grew vertically downwards uninfluenced under 

 these conditions by either light or darkness. 



The second object was to see if water arrested the growth of the 

 primary roots, as in a paper on " A Theoretical Origin of Monocotyledons 

 from Aquatic Dicotyledons " (Joum. Linn. Soc. vol. xxix. p. 486), he had 

 inferred from the great number of coincidences, both in morphology and 

 anatomy, that such must have been the case. One such agreement w T as 

 the total arrest of the axial root in all Monocotyledons, and also in 



