1051

two women are known whose bodies consist of mosaics of

roughly equal numbers of XO and XXX cells. One can

only suppose that such a woman began as a normal XXzygote, but that at its first division " non-disjunction "

occurred with one of the X’s, both of whose daughterchromosomes passed into one daughter cell, and thus ofthe two cells produced one had an X too many and theother an X too few. Not all mosaics arise in this way: thus,for instance, an XXY/XY mosaic may arise by early lossof an X from what was originally an XXY ovum-aremarkable example, if this is true, of accidentalreversion to normal.

Translocation is so far much less important, thoughtranslocations too small to see may be common. A trans-location is an exchange of material between two chromo-somes of different pairs (exchange with the other memberof the same pair is a normal part of meiosis). Simpleexchange between two chromosomes has little immediateeffect (all the genetic material is still there) though theremay be defects arising from imperfections at the newjoints. Since, however, the chromosomes affected are nowdifferent (sometimes very widely different) from theiroriginal partners, they cannot pair off properly duringmeiosis, and irregularities may arise in the offspring inconsequence. Thus in some families a translocation mayexist which has the effect of attaching the bulk of one 21to another larger chromosome: in itself the translocationdoes not matter, and it may be carried through severalgenerations, but it so affects meiosis that occasionalmembers of the family acquire an extra dose of 21 and soappear as mongols, thus giving rise to the most importantvariety (even if rare) of familial mongolism. This is the

only chromosomal anomaly yet recognised as transmissible:all the other anomalies so far known stop at the one case inwhich they appear.There are other kinds of chromosomal lesion, of which

deletion (loss of part of a chromosome) is the simplest,and this has occasionally been blamed for disease in man.

Acquired Chromosome AnomaliesAll the diseases so far discussed are congenital, demand-

ing a lesion already present in the fertilised ovum or (formosaics) its immediate successors. The new techniqueshave so far only increased our knowledge of acquiredlesions in two ways. In the first place, it has been shownthat in most cases of chronic myeloid leuksemia there is adeletion of part of one of the smallest autosomes-a 21 ora 22. And in the second, it has been shown that a singledose of 250 rad of deep X rays to the spine, or 100 mC ofradioiodine, produces a shortlived but surprisingly abun-dant crop of chromosomal anomalies. These are bothprofoundly interesting observations which cannot bediscussed further here..

____

In an attempt to set down the essential facts intelligibly in theleast possible space I have left out all the history, all the people,and all the original references. There are too many of the latterto give them all and to choose would be invidious. If I havefailed to give credit where it is abundantly due, I apologise, butI have at least been consistent. Fortunately, so large a fractionof the formative papers in the subject have appeared in TheLancet that the earnest inquirer is recommended to beginwith the issue of April 4, 1959, and work steadily through allthe issues from then until now, using the index as far as it is

I available. Nearly all the people who matter are represented.You will find it heavy going in places, but most of it makesgood sense, and it is a wonderful story.Weaker vessels may find the editorials of April 4, 1959

(p. 715), Sept. 26,1959 (p. 448), May 4,1960 (p. 1118), July 23,

1960 (p. 191), Nov. 12, 1960 (p. 1068), and Feb. 25, 1961(p. 433), especially the first and the last three, a better historicalintroduction than this, and a useful source of all but the mostrecent references.The mitosis was prepared by Miss Elizabeth Boyd, the photograph

by Mr. G. Kerr, and the diagrams by Mr. R. Callander.

1. See Lancet, 1960, ii, 430.2. Le Milieu Divin. By PIERRE TEILHARD DE CHARDIN. Edited by B. WALL.

London: Collins. 1960. Pp. 153. 18s.

Occasional Book

PUBLISHED OUT OF ORDERFather Teilhard de Chardin’s The Phenomenon of Man 1

was a sensation of the 1959-60 winter reading season,receiving tremendous notice everywhere and bearing thataccolade of the lending section, This book cannot berenewed. Exactly a year later Le Milieu Divin 2 has

appeared, with the following distinctions from its pre-decessor : its title is apparently untranslatable to English,and it has received nothing like the same acclaim. But it isessential reading for a full understanding of the firstvolume. For a remarkable feature of these two bookshas been the editorial decision to release The Phenomenonof Man before Le Milieu Divin, admitting at the sametime what I think most readers would have spotted, thatthe latter was written before the former.

It is a tribute to publisher’s clairvoyance that the hugesuccess came first; but in all fairness the second makes thefirst better, while it would not have made a striking introductionto the series if it had appeared in its natural order. In LeMilieu Divin Father Teilhard’s Christian ethic is clear andconvincing, and he supplies exactly what The Phenomenon ofMan failed to possess. There was an utter lack of divinity inthat book, either revealed, available, or accessible, but LeMilieu Divin is a thesis on the process of

" divinisation ", ofboth our active and our sensory lives, and is deeply moving.

Father Teilhard therefore, or rather his literary executors,have produced two books, at once mutually incompatible andmutually complementary, which is not surprising becausereconciliation is Father Teilhard’s specialty. Thus he is ableon one occasion to stand outside his Christian faith and observethe fallacy of the Christian’s resignation, going so far as toadmit that the pagan loves the earth in order to enjoy it, theChristian in order to make it purer and to draw from it thestrength to escape. The Christian for him is to be at the sametime both the most detached and most attached person, adisparity which he varies between segregation and aggregation(strongly hinting at what is to come in The Phenomenon ofMan), and between development and renunciation. This is

agile reconciliation in all conscience, and he goes further with"

spirituality of matter ", arguing platonically, if not

pantheistically.There should be more volumes to come to the English

reader of Father Teilhard, but already we are verygrateful for the pair which have arrived. Once theirorder is sorted they show the direction of his Christianadaptation to scientism. Father Teilhard was a pioneerof that frontier, as this literary testament is showing, andhe seems to be winning more credit from his fellow cloththan from laboratory jackets. What criticism there wasfor The Phenomenon of Man came from biologists, andthis is inevitable on the premise that a scientist must bedualist towards spirit and fact, while a priest can beuniversalist, and this is Father Teilhard’s very advanta-geous position. He is dealing genuinely in Christiancomfort, which is good European coin, and his editor ispaying it out cunningly.

G. o. J.