244 



Garden and Forest. 



[Number 382. 



neath, two of the hybrids show a closer relation to Betula 

 pumila than to B. lenta. They differ from B. pumila, how- 

 ever, by the greater vigor and larger size of the plants, the 

 much larger fruits, the larger leaves, which are more gen- 

 erally ovate than in B. pumila, with teeth more inclined 

 to be sharply serrate than angularly dentate. 



Whether any of these hybrids would reproduce them- 

 selves in many individuals by sowing the pure seed is a 

 matter for further experiment. The present instance seems 

 to show how freely the Birches may hybridize with each 

 other when two or more species are growing near together 

 and flowering at about the same time. But, when growing 

 naturally, although many ovules might be fertilized by pol- 

 len from another species, it would be a rare case that one of 

 the perfected seeds should develop into a mature plant, as 

 not one seed in tens of thousands gets a chance to grow. On 

 the other hand, under conditions of artificial propagation 

 and cultivation, a large proportion of the seeds sown are 

 expected to develop into plants, and it is under these cir- 

 cumstances that the fact of the frequency of hybridity be- 

 comes apparent. It is made especially clear when it occurs 

 among such dissimilar species as Betula pumila and B. 

 lenta, where the intermediates are so distinct that hasty 

 students might be led to give them new specific names. It 

 may be worth mentioning that Mr. C. E. Faxon and other 

 botanists have found in various parts of New England what 

 appear to be undoubted hybrids between B. papyrifera and 

 B. populifolia. 



The drawing prepared by Mr. C. E. Faxon represents 

 the character of the flowering of one of the hybrids between 

 Betula pumila and B. lenta, the appearance of the foliage 

 and fruit of another, an enlarged scale and nutlet from the 

 fruit, a typical leaf of B. lenta and one of B. pumila, the 

 latter being somewhat larger than the average. 



Arnold Arboretum. J* ^- y^cU. 



Entomological. 

 New Facts about Scale Insects.- 



-I. 



JUST now the study of scale insects and mealy bugs, 

 Coccida2, is progressing more rapidly than ever before ; 

 and, perhaps, more than at any previous time, horti- 

 culturists are awakening to the importance of this subject 

 in its relation to their industry. Last year (1894) nine 

 authors described between them forty-two new species of 

 Coccidse. This year there will be more writers, and the 

 amount of work ]jublished will be very mnch greater. 

 Mr. E. E. Green, of Ceylon, will alone publish over forty 

 species ; Mr. Maskell has a paper now in press, doubtless 

 containing a great deal that is new ; I have nearly forty 

 species awaiting publication. Very probably the Coccidse 

 described in 1895 will not fall short of 150, a very much 

 greater number than heretofore described in any single 

 year. The total number of Coccidae so far published is 

 only about 750. Of these, it may be remarked, about 175 

 are to be credited to Mr. Maskell. 



It is singular how easily a species may be overlooked. 

 Most Coccids are inconspicuous ; but, what is more cu- 

 rious, they are so often extremely local in their distribu- 

 tion, even where the food-plants abound. Atriplex canes- 

 cens is one of the commonest plants found at Las Cruces, 

 New Mexico. Two days ago I noticed, on my way home 

 from the Agricultural College, a plant more or less covered 

 by what looked like the seeds of Phoradendron, so often 

 seen on trees about here. Hesitating a little as to the 

 actual nature of the appearance, I stooped and picked a 

 twig. To my astonishment the apparent seeds were speci- 

 mens of a new and very remarkable Coccid. Though 

 numerous on this particular plant, it had never been seen 

 on the Antriplex growing all round the locality, which I 

 had often examined ; and what is more, I had passed this 

 very plant on my way to and from college ever since the 

 middle of 1893, and had seen nothing. 



The creature is so peculiar that I thought it would form 



a new genus ; but for the present it may be better placed in 

 Eriococcus as E. neglectus, n. sp. 



Last week I spent part of two days at the Dripping 

 Spring, in the Organ Mountains, near here, about 5,600 

 feet altitude (1,800 feet higher than Las Cruces). On the 

 wild Oaks I found two species new to the locality — Kermes 

 galliformis, Riley, which seems to be very widely dis- 

 tributed in the United States, and Chionaspis Quercus, 

 Comst., hitherto known only from California. The latter 

 appeared to have killed many of the twigs and smaller 

 branches, and would, doubtless, be a very troublesome 

 pest on Oaks cultivated for ornament, should it get taken 

 east. Sitting down to rest after climbing a few hundred 

 feet above the camp, my eye fell casually on an Opuntia 

 (which Professor Wooton tells me is O. Engelmanni). 

 Some white spots on it suggested a closer inspection, and 

 proved to be Diaspis Cacti, Comstock. Now, why should 

 this scale be found up there on a single Cactus-plant, and 

 not be observed anywhere else in the vicinity or in the val- 

 ley below, though species of Opuntia abound.? This D. 

 Cacti was described from specimens causing serious trouble 

 on cultivated Opuntia-plants in the east, and its native 

 habitat was unknown until Professor Toumey lately found 

 it plentifully in Arizona. 



I have been making an effort to find out what Coccids 

 exist on Palms throughout the American tropics, and to that 

 end addressed letters to a number of consuls in localities 

 whence no Coccids had hitherto come. So far two replies, 

 with specimens, have come in. A piece of Palm-leaf from 

 Mr. J. D. Hall, United States Consul at San Juan, Porto 

 Rico, is very sparsely infested with Aspidiotus destructor, 

 Signoret. Mr. Hall explains that the Palm was a young 

 Cocoanut in cultivation. Mr. F. Wolff, Acting German 

 Consul at Jacmel, Hayti, was very obliging, and sent por- 

 tions of leaves of Oreodoxa regia and Cocos nucifera. Both 

 were sparsely infested by a single species, Aspidiotus Ficus, 

 Ashmead, which is new to Hayti. 



The California people ought to be much obliged to Mr. 

 Craw for the way he is heading off troublesome Coccids 

 about to be introduced into that state. Mr. Flhrhorn sent 

 me the other day the following species, lately found by 

 Mr. Craw in his quarantine work : Ceroplastes rubens, 

 Maskell, on a Fern from Honolulu ; C. ceriferus, Anders., 

 on Camellia from Japan; Chionaspis biclavis, Comst, on 

 Orange from Tahiti ; Asterolecanium pustulans, CklL, van, 

 an unknown shrub from Mexico. The last is a particularly 



pernicious species. 



New Mexico Agricitlt'l Experiment Station. 



r. D. A. Cockerel!. 



Plant Notes. 

 Viburnum cassinoides. 



SOMETHING like a dozen species of Viburnum are 

 natives of eastern North America, and all of them are 

 such good garden plants that we make no apology for 

 repeating what we have said in their commendation year 

 after year ever since this paper was founded. Like our 

 native Cornels, their worth has never been thoroughly 

 appreciated by planters, and there are many large collec- 

 tions of shrubs in public and private grounds of this coun- 

 try in which hardly a representative of either of these 

 interesting genera can be found. The Viburnums are very 

 beautiful when growing wild, and sometimes they display 

 their best points on the wood borders, but in order to 

 realize all their good qualities one has to see well-established 

 plants after careful cultivation in good soil. These plants 

 in masses and in single specimens make one of the most 

 useful object-lessons which the Arnold Arboretum is furnish- 

 ing to its thousands of visitors every year. Our native 

 shrubs have here been planted so abundantly that their 

 good and bad qualities are evident to any one who 

 cares to study them. V. cassinoides, as seen in the gar- 

 den, is certainly very different from the spindling plants 

 which are usually found wild in swamps. In rich ground 



