444 



PROF. AV. N. F. WOODLAND ON LIGATURING THE 



and the wound cleansed with weak carbolic acid, carbolic ointment 

 being rubbed on the surface. While the wound was liealing, I 

 covered it with a pad of cotton wool, protected with a waterproof 

 sheet, the four corners of which were drawn out and tied anteriorly 

 above the scapulse and under the animal's throat, and posteriorly 

 over its back. The animals were given an occasional bath in 

 shallow distilled water (the skin having previously been w^ell 

 cleaned), but were normally kept dry, the pad protecting the 

 wound from urine and faecal matter in the basin. 



Out of 11 toads operated on as above described (save that I 

 only ligatured the anterior abdominal vein in one place) in 1915, 

 one lived for ten days, one for fourteen days, one a day short of 

 eight weeks, and two others w^ere killpAl after eight weeks and 

 eleven w^eeks respectively. 1 shall only record my examination 

 of the three long-period sui-vivors, all of whicli w^ere operated on 

 on October 1st, 1915, and the wounds healed by October 12th. 

 A day or so later they w'ere all active and feeding w^ell. 



One, as already stated, died on November 20t]i, one day short of eight weeks 

 after the operation. It was very thin, and had been ill durino- the previous week. 

 It weighed at death (after suljtracting weiglit of food in gut) 2i*5 gnis. The heart 

 was normal in size (heart ratio =229"0 *) ; the liver a trifle largo (liver ratio = 21-5 *). 

 The liver was very diseased, being full of small cysts; the spleen was much enlarged 

 and also full of cysts, and the fat-bodies very minute. Sex not recorded, i'iie 

 anterior abdominal vein was found to be well ligatured and was ((uite eni])ty ; on the 

 other hand, the renal afferent veijis and post-caval were very large, and the two 

 kidneys (quite healthy) were gorged \»ith venous blood and therefoi'e rather diirk in 

 colour. It is important to note that a neto anterior abdominal veiv had not heen 

 formed. The kidneys, after as usual being slightly squeezed and all attached vessels 

 removed, weighed together 0*230 gm., and were therefore apparently enormovsly 

 enlarged (kidne}^ ratio = 93*o*, bodj'-weight taken at death). 



The toad (a male) which I killed on Noveml)er 28th — eight weeks and one day 

 after the operation^ — was perfectly healthy, being active and feeding well, and all tlie 

 internal organs in perfect condition. In this toad I found to my surprise that a new 

 vein had heen formed posterior to the ligature and entering the liver, also tiro or 

 three small new veins coming from the muscles of the anterior ventral hody-wall and 

 opening into the principal ne w vein (text-fig. 1, 13) f . The body-weight (after weight 

 of food in gut subtracted) was 21*9 gms. The heart ratio was 199"3*; the liv(>r 

 (weighing exactly 1*0 gm.) ratio = 23'9 the kidney ratio = I(U'8 The kidneys, 

 therefore, were about normal in size. 



The remaining toad (a male) 1 killed on December 18th — eleven weeks after the 

 operation — and this also was in perfect health inside and out. In this toad also a 

 new vein had heen formed to allow the ligatured anterior abdominal to become 

 functional. The body-weight was 30"0 gms. The heart ratio = 229'0 * ; the liver 

 ratio = 19*6*; the kidney ratio = 157'9*. The kidneys, therefore, were about normal 

 in size. 



* The normal (average) ratio— ^ ' " ^ for the heart (all vessels cut off and 



vv lit or viscus 



all blood washed out and dried) in these toads is 216'8 (determined in 29 toads) ; the 

 normal ratio for the liver (squeezed and dried) was 28"4 (18 toads) ; the normal ratio 

 for the kidneys (wt. of both kidneys, attached ureters and vessels being removed) 

 was 237"5 (82 toads), I must add, however, that in two other lots of toads the 

 average kidney ratios were 155"2 (10 toads) and 159'3 (6 toads). The kidney ratio 

 (also the heart and liver ratios) shows great variations, not connected with the time 

 of year or with sex. 



f Compare the " rapid formation of a collatei-al circulation so that the blood could 

 get round the ligature to the lii er " (Starling, ' Principles of Human Physiology,' 

 1912, p. 858) when in a mammal the portal vein was ligatured off from the liver and 

 made to open into the posterior vena cava. In this case, however, the liver is 

 deprived of blood from the gut and not merely of an additional su])ply of ordinai-y 

 yenous blood, as in the toads with ligatured renal afferent veins. 



