[21]

In Dr Grays Manual there are 689 genera with 2004 species subtracting the 369 genera with single species, we have 689 [-] 369 [=] 320

2004 2004

2004 [-] 369 [=] 1635 [÷] 320 [=] 5.11

So that the genera excluding the genera with single species have 5.11 species per genus. —

But Dr gray has not marked in his M.S list Salix: with 22 sp & as Carex has so very many viz 126 (with many of these close) these two may be left out. Then we shall have 318/1638 [-] 148 [=] 1487 1 /4.67

(If we further leave out aster with 35 sp. & solidago with 31 species

(no good reason to do this) [calculations not transcribed]

Now Asa Gray has marked for me 115 genera with 733 close species (N. B he has marked more than half the species (with Carex Salix & species of single genera omitted)); therefore, but the species of Salix & carex here omitted, now these 115 genera have on average (115/733 (6.37) whe but the other genera, ( see above) with which this number is comparable, have on average 4.67; hence the genera with "close species" have 1.7 on average more species. — How funnily the same as H. Watson viz 1.68 see Back

(If aster with 35 sp & solidago with 31 sp be omitted then the genera with close species have only 5.90 species on average, & 4.49 is standard of comparison, but I see no good reason to omit these genera.)

In the Manual, subtracting the genera salix & carex, & the 369 genera with single species, & 121 genera with 2 species, there is left 197 genera having more than 2 species in each. These species amount 1245. Therefore each genus has on average 6.32 species; But the 32 genera marked in Dr Grays list, as having 3 or more species "close" have on average 11.28 species: so that same result brought out very strong. (even if aster & solidago be omitted the average is 9.50 so much larger than 6.32.)

[21v]

In Dr Gray Manual these 532 genera with 1431 species now subtracting the 369 genera with single species, we have

532 [-] 369 [=] 163

1431 [-] 369 [=] 1062 [÷] 163

[21]

Genera with 3 or more "close species", abstracted from Dr. Grays M.S. List

no' species in Genus Ranunculus 16 Viola 17 Silene 12 Cerastium 5 Polygala 13 Œnothera 7 Viburnum 9 Hedyotis 5 Liatris 5 Eupatorium 13 Aster 35 Solidago 31 Helianthus 16 Artemisia 6 Nabalus 9 Dipleuranthus 3 Gerardia 8 17 210

no' species in Genus Onosmodium 3 Cuscuta 7 Polygonum 20 Callitriche 4 Quercus 18 Abies 5 Corallorhiza 4 Platanthera 16 Juncus 20 Cyperus 15 Suipus 14 Agrostis 6 Poa 10 Festuca 6 Triticum 3 15 151 [calculations not transcribed] 17 32 So that these genera have on average 11.28 species per genus.

[21a]

Another & fairer way of working is this. The genera which have not close species are (318 - 165 =) 203 & these include (1487 - 733=) 754 species, so that 203/754 (3.71

The genera with close species having 6.37

May 15/56