hence Conifers with relatively simple floral organization show little that is conspicuously 

 striking in teratology. (Penzig, 1894.) 



Note: Since any factor may go wrong at any time, it follows that every possible 

 case of malformation will be met with sooner or later, if only a sufficient number of 

 individuals be examined ; the more the trees are cultivated and observed, the more 

 such irregularities are recorded. Hence there may be abundant literature dealing with 

 Pinus sylvestris, Larix europaea, and Picea excelsa, but less with rarer types. Such 

 tendency to error is again commonly increased by intensive cultivation and by ' over- 

 feeding'; i.e. giving a plant much better conditions and more favourable food-salt 

 supply than the race has been used to. Hence freaks, sports, and monstrosities 

 abound in garden and nursery practice, and if curious may be retained in cultivation 

 (cf. variegated forms, weeping forms (pendula vars.), dwarf forms (nana vars.), or 

 fastigiate forms (vars. fastigiata, virgata), and Retinospora forms of Cupressus with 

 juvenile leaves. (Veitch, 1900.) The more commonly observed cases may be classed as : 



I. Anomalies in the mechanism of centric shoot organization, and the relation 

 of stem and leaf. 



(1) Phenomena of Fasciation include the case of growing-points with multiple 

 centres, commonly bilaterally arranged to give banded, crested, and irregularly branched 

 formations. Examples are general; cf. more particularly Larix europaea, also 

 P. sylvestris, with fasciated cones ; rare in P. austriaca, P. Laricio, Picea excelsa, 

 Abies peclinata, Juniperus commimis. Possibly the finest case on record is given by 

 Baker (1910, p. 333) for Arancaria Cunninghamii, an entire tree being thus malformed. 



(2) Multiple shoot-systems producing irregular masses in which internodal extension 

 is omitted may give massive growths (up to i-i^ ft. diameter, and attaining a weight 

 of several pounds in Pinus sylvestris) bearing densely clustered leaves peripherally : 

 these growths do not necessarily involve any outside stimulus of fungus or insect. 

 Similar shoot-systems, as closely compacted woody masses, and buried beneath the 

 bark, produce no leaves but consist of a mass of labyrinthine annual rings. These 

 constitute ' burrs ' or ' knauers '', and may attain considerable size ; they are general in 

 all tree-forms and are occasional in Conifers ; cf. Cedrns. 



(3) Minor variations in phyllotaxis-constants are generally too inconspicuous to 

 attract attention ; but are recorded for cones of Pinus, Picea ; poorly grown plants 

 commonly give irregular constructions. A break to trimery in Thuya is more 

 interesting. 



(4) Irregularities in restricting the number of leaves on foliage-spurs of 2-needled 

 Pines may apparently express a reversion to an older phase ; rare in P. sylvestris, 

 P. montana, 3 for 2 ; but also 3 for 5 in P. Cembra, and 2-3-5 on strong stump- 

 shoots of P. rigida ; and again i for 2 (P. edulis) as in normal P. monophylla. 



(5) Dichotomy of the growing-point, giving twin-centres, is noticeable in the case 

 of apparent ' twin-cones ', or species with a forked apex ; P. Cembra, P. sylvestris, twin- 

 cones, also in Larix and Picea excelsa ; again interesting in a dichotomous staminate 

 flower, Cedrus Libani. 



(6) Suppression of lateral growth-centres, if of all kinds, gives the case of the 

 monaxial plant as the 'disbudded mutant', Picea excelsa, Abies pectinata\ or in 

 advanced Pines the case of suppression of leaders only, giving a monaxial stem with 

 foliage spurs (P. austriaca). 



(7) Failure in normal geotropic response and mechanism, as in dwarf and 

 prostrate varieties : P. sylvestris, prostrate ; Abies pectinata, Picea, with long horizontal 

 shoots ; prostrate Cupressus sempervirens. 



Tending to negative response in laterals, giving fastigiate varieties, Spruce, Taxus, 

 Cupressus Lawsoniana, Taxodium distichum. 



Or tending to positive response in pendula vars., Sequoia gigantea, Pinus Strobus, 

 P. sylvestris, Larix, Picea, Abies, Cedrus Deodar a, Thuya, Cupressus Lawsoniana. 



(8) Virgata forms (' serpent ' forms): primary branches with no or few secondaries, 

 Pinus Laricio, P. sylvestris, Picea excelsa (with the habit of an Araucaria], 

 Pseudotsuga Douglasii, A bies pectinata, &c. 



II. Anomalous segregation of lateral growths : Given 10 sorts of leaf-member 

 and 5 types of shoot in Pinus sylvestris, mistakes may be excusable, and such errors 

 may give conspicuous results, cf. : 



(i) Formation of leaders instead of spurs in Pinus has been regarded as a relic of 



25 



