WCP1478

To Thiselton-Dyer, Esq. Pen-y-bryn, St. Peter's Road, Croydon.

Jan'[uar]y. 2nd. 1881

My dear Mr. Dyer

Many thanks for your letter & valuable notes; as to which I will make a few remarks.

1. Helianthemum Breweri. In Mr. H. C. Watson's letter to me he seemed to think that this was, at all events, a "variety" & that it was unknown on the Continent. Mr. A. Bennett of this town also thinks considers it to be a distinct form from Hgaltatum.(?)

2. Oenanthe fluviatalis[sic] is thought by Mr. Bennett to be very distinct, — but as you have it from France it must be omitted.

3. Arenaria ciliata. I omitted. the Arctic range, (I don't know why!) but both Wood's Tourist Flora & Bentham's Brit[ish]. Flora give S[outh]. European localities.

4. Mr. A. Bennett assures me that Potamogeton lanceolatus (Smith), which Mr. H. C. Watson did not mention to me, is quite distinct from all known European forms & is up to the present time restricted to the British Isles. I must therefore add this.

The difficulty of getting at the truth in these matters seems very great, not only from the difference of opinion as o what are species, sub-species, varieties, or states, but also from the constant discoveries of plants in new localities, from erroneous identifications &c. &c.. The opinion seems to be so very general that there were really no real peculiarities in the insects or plants of Britain, — and this seemed so improbable to me both on à priori grounds, & from the undoubted peculiarities among birds and fishes, that determined to bring together what cases I could find recorded. I hope that my having done this (very imperfectly as regards plants) will induce a some of our British Botanists to devote special attention to the subject, which seems to me so interesting that I think it would be worthy of attention of a Committee, who should publish every year a list of the permanent forms (whether sp[ecies], sub-sp[ecies]., or var[ieties].) not yet known beyond the British Isles, — or not on the Continent, — or in only one or two localities on the Continent. Of course I know nothing of these plants myself, and thought that in applying to Mr. Mor Mr. Watson & having the assistance of Mr. Bennett (to whom however I applied too late) I should get all that was known on the subject. As to the mosses & hepaticae I trusted wholly to Mr. Mitten, to whom I will send the portion of your letter that refers to them.

p. 491. I took the statement about the Compositions of the Southern Islands from the "Int[ernational][?] Essay on the Flora of N[ew]. Z[ealand]." p. XXI. Note "this of the Compostae, common to Lord Auckland's Group, Fuegia, and Kerguelen's Land, none have any pappus at all! "The "none" seemed to me to imply necessarily that there were "several" species common to these islands; and as Sir J. Hooker looked over my proofs & did not correct this I did not think it necessary to enquire further.

p. 490. Greenland — In Nature XXI — p. 345 is a statement of the discovery of rocky peaks far on the ice from which 54 species of plants were collected.

p. 494. — My conclusions as to the permanent separation of S. Africa and Australia are derived from general considerations & on the whole evidence of the page history of the Earth both physical & biological as I view it.

I had read your lecture on "Plant Distribution" with great interest, but I did not remember any reference to this point; & on now looking at it again I fail to discover it. At p. 430 you say, of the S[outh]. Af[rican]. flora, "its affinities with the Australian, which do not extend beyond groups of the highest order have already been described"[.] But in the preceding account of the Australian Flora I find no reference to this point.

I know nothing of the Restiaceae except their being classed near Cyperacaea & Juncaceae. Would "low stage of development" be more accurate. But surely they are low as compared with most orders of flowering plants; — & what I meant to imply was — probable great antiquity under their present form, & this would be compatible with "great differentiation" in the sexes.

I should be very glad of your opinion & criticisms on any other points that occur to you.

Yours very faithfully Alfred R. Wallace

(1)¹

To Thistleelton-Dyer², Esq.) Pen-y-bryn, St.Peter’s Road, Croydon.

Jan’y.2nd.1881

My dear Mr.Dyer

Many thanks for your letter & valuable notes; as to which I will make a few remarks.

1. Helianthemum Breweri. In Mr.H.C.Watson’s letter to me he seemed to think that this was, at all events, a "variety"³ & that it was un-known⁴ on the Continent. Mr.A.Bennett of this town also thinks con-siders⁵ it to be a distinct form from H.ggaltatum⁶. (?)

2. Oe nanthe⁷ fluviatalis is thought by Mr.Bennett to be very distinct, — but as you have it from France it must be omitted.

3. Arenaria ciliata. I omitted⁸. the Arctic range, (I don’t know why!) but both Wood’s Tourist Flora & Bentham’s Brit[ish]. Flora give S[outhern].European localities.

4. Mr.A.Bennett assures me that Potamogeton⁹ lanceolatus (Smith), which Mr.H.C.Watson did not mention to me, is quite distinct from all known European forms & is up to the present time restricted to the British isles. I must therefore add this.

The difficulty of getting at the truth in these matters seems very great, not only from the difference of opinion as to what are species, sub-species, varieties, or states, but also from the constant discoveries of plants in the new localities, from erroneous identifi-cations¹⁰ &c.&c.. The opinion seemed to be so very general that there were rea ly¹¹ no real peculiarities in the insects or plants of Britain, — and this seemed so improbable to me both on à priori¹² grounds, & from the undoubted peculiarities among birds and fishes, that I determined to bring together what cases I could find recorded. I hope that my having done this( very imperfectly as regards plants) will induce a some of our British Botanists to devote special attention to the sub-ject¹³, which seems to me so interesting that I think it would be worthy of attention of a Committee¹⁴, who should publish every year a list of the permanent forms (whether sp[ecies]. sub-sp[ecies]., or var[ieties].) not yet known beyond the British Isles,- or not on the Continent,- or in only one or two localities on the Continent. Of course I know nothing of these plants myself, and thought that in applying to Mr. War [2]¹⁵ Mr.Watson & having the assistance of Mr.Bennett ( to whom however I applied too¹⁶ late) I should get all that was known on the subject. As to the mosses & hepaticae I trusted wholly to Mr.Mitten, to whom I will send the portion of your letter that refers to them.

p.491. I took the statement about the Compositae of the Southern Islands from the "Int[ernational].Essay on the Flora of N[ew].Z[ealand]." p.XXI. Note "Thus of the Compositae, common to Lord Auckland’s Group, Fuegia, and Kerguelen’s Land, none have any pappus at all! " The"none" seemed to me to imply necessarily that there were"several"species common to these islands; and as Sir J.Hooker looked over my proofs & did not correct this I did not think it necessary to enquire further.

p.490. Greenland — In Nature XXI-p.345 is a statement of the dis-covery¹⁷ of rocky peaks far on the ice from which 54 species of plants were collected.

p.494.- My conclusions as to the permanent separation of S[outh].Africa and Australia are derived from general considerations & the whole evidence of the past history of the Earth both physical & biological as I view it.

I had read your lecture on "Plant Distribution" with great interest, but I did not remember any reference to this point; & on now look-ing¹⁸ at it again I fail to discover it. At p. 430 you say, of the S[outh].Af[rican].flora, "Its affinities with the Australian, which do not ex-tend¹⁹ beyond groups of the highest order have already been described" But in the preceeding account of the Australian Flora I find no reference to this point.

I know nothing of the Restiaceas except their being classed near Cyp-eraceae²⁰ & Juncaceae. Would "low stage of development" be more accur-ate²¹. But surely they are low as compared with most orders of flower-ing²² plants;- & what I meant to imply was — probable great antiquity under their present form, & this would be quite compatible with "great differentiation" in the sexes.

I should be very glad of your opinion & criticisms on any other points²³ that occur to you.

Yours very faithfully | Alfred R.Wallace