10 TIIK JOURNAL OF EOT ANY 



is due in 16 cases to the interpolation of a single simple pair, and 

 in 7 cases to the interpolation of two successive simple pairs. Th-e 

 single simple pair is the second pair in 9 cases, the third pair in 

 5 cases, and the first pair in 2 cases. The two successive pairs are 

 the second and third in 6 cases, and the first and second in one 

 case. Out of 30 interpolated simple pairs, 16 are in the second 

 pair, 11 in the third, and 3 in the first. 



The bifoliolate leaves are usually composed of a terminal leaflet 

 and a lateral one, rarely of two lateral leaflets. In the case of 

 a bifoliolate pair one leaf is sometimes the mirror-image of the other, 

 owing to the right lateral leaflet being developed in one leaf and 

 the left lateral in the other; in other cases it is the two right 

 laterals or the two left laterals which are developed. No correlation 

 was found between vertically superposed anisomerous pairs : some- 

 times the more developed leaf was above the more developed one of 

 the pair below, but the reverse arrangement occurred about as 

 frequently. 



Four tricotyledonary seedlings were found. Two were of the 

 formula 3 -j- 2 -j- 1, i. e. had a whorl composed of a trifoliolate, a 

 bifoliolate, and a simple leaf, alternating with the cotyledons and 

 followed by continuously simple pairs. In one of these seedlings 

 a solitary simple leaf above one of the cotyledons intervened between 

 the 3 + 2 + 1 whorl and the series of simple pairs. The third seedling 

 was of the type 3 -f 3 + 2, and the fourth was 3 + 3 + 3; 3 + 1 + 1, 

 simple pairs following on in both cases. As about 300 dicotyle- 

 donary seedlings had to he rejected as being too undeveloped for 

 examination, the tricotyledonary seedlings formed approximately 

 0'5 per cent, of those collected. 



Boodle found in TJ. europceus that backward seedlings produced a 

 lower average of compound leaves than those which develo))ed earlier. 

 The same appears to be the case in Z7. Gallii. The seedlings were 

 collected in two batches, those of the second batch being considerablv 

 more developed than the first. In the first batch only 2 per cent, 

 had compound leaves extending to the fourth or fifth pairs, while in 

 the second batch 15 per cent, had compound leaves up to the fourth, 

 fifth, or sixth pairs. In the first lot the seedlings were taken as they 

 came, while in the second lot collected a few days later the largest 

 ones were selected in order to facilitate examination. 



To sum up : 96"6 per cent, of the seedlings of TI. Gallii bore 

 from 1 to 11 compound leaves after the cotyledons and before the 

 continuously simple leaves. 48-8 per cent, had both leaves of the 

 first pair trifoliolate and all the following simple. No compound 

 leaves were found after the sixth pair, and the percentage of com- 

 pound leaves diminished progressively from the first pair onwards. 

 The series of compound and mixed pairs ma}^ be preceded or inter- 

 rupted by one or two simple pairs. 



The ratio of trifoliolate to bifoliolate leaves diminished progres- 

 sively from the first pair to the third : in the first two pairs trifolio- 

 late leaves were more numerous than bifoliolate ones, while in the 

 third pair the reverse was the case. In the fourth, fifth, and sixth 



