428 



THE C'HKMICAL KXA.MIN A'i'lOX OF .\lA(,'I!OZA.MIA .SPIHALIS, 



these animals suffering with Zaiuia paralysis, some being recent acute, others old 

 chronic cases, the author took blood, spinal and synovial fluids, and emulsion of 

 cord, and injected these into other healthy cattle. He failed in all cases to infect 

 the latter. He remarked that no case of disease had ever been produced by in- 

 jecting hypodermically, or by internal dosing with any substance extracted or 

 isolated from Macrozamias, but only by feeding with the plant itself. After long 

 persistence in feeding with the ])Iant, the j^ractical pennanence of symptoms 

 was associated with peripheral neuritis (20) . 



Similar conclusions were arrived at by Professor Smith, of Sydney Univer- 

 sity, as a result of his experimental work. 



Mr. J. H. Maiden descriljed a convincing instance of cases of poisoning in 

 1895-1898. In a paddock in which Macrosamia plants were growing, stock were 

 badly affected. The cattle were removed and the cycads cut down completely, 

 but left lying in the paddock. Next year the stock were put back, and in six 

 weeks were again suffering badly. Their stomachs were filled with the dried 

 Macrozamia leaves. In 1897, the paddocks were closed again, till after one year 

 cattle were admitted. They ate the dried withered leaves and all became ill. 

 In 1898 the withered leaves had all disappeared, and only the roots were left, 

 which had been dried for over 3 years. Cattle, when i)ut in again, ate the 

 roots, and became ill as before (16) . 



Professor J. D. Stewart, in 1899, then chief Veterinary Officer for New 

 South Wales, conducted an enquiry into an outbreak of the disease at Moruya. 

 A hundred head of cattle of all ages were affected. The symptoms were ob- 

 served in all stages, and were described in detail and illustrated by photographs. 

 Post-mortem examinations also were conducted. These led to the conclusion of 

 the existence of partial motor-paralysis of the hind extremities, due to loss of 

 nervous control over the actions of the muscles of the parts affected (21). 



In the following year. Professor Stewart caiTied out feeding experiments on 

 cattle. He gave each 2 lbs. per day mixed with cliaff. Symptoms of the disease 

 were indicated on the 23rd day, and the condition tlioroughly established in all 

 its manifestations 8 days later. This condition was shown to be permanent, and 

 for all practical purposes incurable (22) . 



In 1906, Mann and Wallas analysed Macrozamia Fraseri, the Western Aus- 

 tralian species, and concluded that the effects upon cattle induced by eating the 

 plant are caused by potassium oxalate [confirming Norrie's result on 1/. spiralis 

 (5)]. The authors referred to the plant but did not say whether leaves or nuts 

 were used (24) . 



In 1912, Inspector Marks was sent to the Tabulam district. New South 

 Wales, where in 1900 over 400 cattle had died. Heavy losses had been experi- 

 fnced each succeeding year till at last the leases had been given up. Zaniia 

 eaters with the confirmed luibit had taught the whole herd, though plenty of 

 green fodder was available. After some yeai-s, this neglected land was again 

 leased for grazing and the herds were at once affected, there being many fatalities 

 (25). 



Dr. Cleland carried out feeding experiments on Milsou Island in 1912 and 

 1913. The leaflets of M. spiralis were cut up small and mixed witli cliaff, 1 to 2 

 lbs. per day being given to each animal which was then well fed with other 

 nourishing food. These experiments were of 5 months' duration, and no signs 

 of any poisoning effects were discovered. The author's comment is that if 



