306 



the plant.* Carex vesicaria and Equisetura limosiim, both in an iin- 

 branched and branched state, were picked at Loch Skiros. 



On examining some of the Carices and grasses, it was found that 

 the rule in regard to the solid stem in the former and the hollow stem 

 in the latter was not universal. Thus Carex remota and ovalis had 

 distinctly hollow stems, while Ammophila arundinacea had a solid 

 stem. This grass is said by Dr. Parnell to be the only British one 

 with a stem always completely solid.f It also differs from other 

 grasses in not having a striated stem. It may also be remarked here, 

 that in the Umbellifera3 the character founded on the fistulose stem 

 does not invariably hold good, for on the same root solid and fistulose 

 stems will be occasionally found. 



Many of the grasses in Islay displayed much of the ergot, or that 

 disease which is common in rye, and which is an altered state of the 

 ovary caused by the attack of a fungus, Ergotsetia abortifaciens of 

 Quekett. This plant produces sporules, which communicate the 

 disease to healthy grain, either by being directly applied, or by being 

 taken up from the soil. Mr. Quekett has produced the disease arti- 

 ficially by watering healthy plants of rye with water containing the 

 sporules. Proper draining will probably prevent the attack of ergot. 

 Ergot injures the quality of the flour, and cases are detailed in which 

 the use of diseased rye has caused dry gangrene. The disease is not, 

 however, peculiar to rye ; it occurs in many grasses. Professor 

 Henslow has observed it in wheat in Suffolk, and in the district in 

 which he saw it, it is stated, that about a century ago, several cases 

 of poisoning occurred from diseased wheat. Our party observed 

 ergot in considerable quantity on Anthoxanthum odoratum, and on 

 Phalaris arundinacea. The former grass is very abundant in many 

 parts of the island, and is well deserving of cultivation. Besides the 

 ergot, we noticed the disease in oats caused by a species of Uredo, 

 and commonly called smut. In many fields the disease was very pre- 

 valent. It is said to be prevented by steeping the grain in stale urine 

 and afterwards sifting lime on it. A solution of salt and a weak solu- 

 tion of sulphate of copper have also been employed. 



August 19th. —The day was very unpromising, and thick mist and 



* On examining the peduncle of Nymphasa alba lately, in Bute, I detected hairs 

 in its tubes as well as in those of the petiole. The same thing was seen in the pe- 

 duncles and petioles of Nuphar lutea. In the latter plant, the air-tubes in the petiole 

 were larger than those in the peduncle, and displayed the hairs most distinctly. 



f See Dr. Parnell's able work on British Grasses. Broraus patulus and some other 

 foreign grasses have also solid stems, and Mr. Gorrie has noticed the same occurrence 

 in some varieties of wheat. 



